"Who's Foster, who's Luke?"

Seven-year-old Luke giggled excitedly and bounced lightly on the bed he shared with Foster. He leaned in and listened to what his twin was whispering.

"Mum and dad won't know," Foster whispered. "I bet you they won't."

"But they'll see us!" Luke argued. "Dad knows we're not the same right here."

Foster chuckled when Luke pointed to his crotch wearing only their white briefs. Luke pouted and looked at his twin seriously.

"I'm seewious!"

"Serious," Foster corrected. "With an `r' silly!"

"Yeah! Seewious!"

Foster giggled at the look that Luke was giving him. His twin was `seewious', alright. Very `seewious'. He moved closer to Luke and pulled the seam of his twin's briefs to look at the little package inside.

"It'll grow, Lu," he said. He was the only one allowed to call his brother Lu. He'd get really mad when others called Luke that way.

"But yours is already big," Luke said, his pout never leaving his face. His eyes were fixed sadly on his willy. Foster's hand pulled the front of his undies some more and the little package only seemed to shrink into his groin.

"Mum and Dad won't know," Foster told him. "I'm sure of it."

"But they will! Our clothes have name tags on it," said Luke, pointing to the tiny stitch on seam of his underwear that spelled out his name. "If we switch clothes, they'll know we did. It'll be obtuse!"

"Obvious," Foster once again corrected, giggling at his brother's poor vocabulary.

"That's what I said. They'll know who's Foster and who's Luke."

As genetics would have it, the twins had no visible birthmarks to set them apart. Their skins were fair and soft with no marks whatsoever. Well, not totally. The only two things that could set them apart were the size of their peckers and that little mark right under Foster's left foot. That's why their dad fondly called him Achilles. When the twins were dipped into the same gene pool, Foster apparently had his left foot sticking out.

"We won't wear anything," said Foster. "Not even our undies."

"But..."

"We'll keep our hands over our willies and we'll tell mum and dad that they can't look at it."

"What about your foot?"

"They can't look at it either."

Luke thought about it for a moment, then a smile replaced the pout on his lips. He nodded eagerly and Foster immediately stood on their bed and took off his briefs. Luke followed and soon they were as naked as the day they were born. From anyone's viewpoint, it was very easy to tell who's Foster and who's Luke. That's why Foster quickly put a hand over his crotch, bringing his tight balls up close to his pecker.

"See?" he said.

"Uh-huh!" Luke nodded and also put a hand over his boyhood. "They won't know for sure."

The twins hopped off the bed, leaving their undies with their names stitched onto it on the sheets, and went to look for their parents. They ended up in the living room with their mum and dad curiously staring at them.

"Who's Foster!" Luke shouted.

"Who's Luke!" Foster chuckled.

Their voices sounded the same, the fringes of their brown hairs were cut to the same length while the rest of their hair was still a mess from just waking up after their nap. They had the same contagious smile that only a little boy was able to pull off. Their pale green eyes shone with mischief and childishness.

"Can we have a closer look?" their mum asked.

"Nope!" they both said.

Their dad smiled knowingly and was amused at how the boys kept both their hands over their groins. He scanned their bodies, but to no avail. Even their navels crept into their tummies similarly.

"Can you switch places for me?" he asked.

The twins looked at each other until they both decided telepathically that it would do no harm to switch places. In fact, they thought that they were both doing a magic trick the same way someone would ask to find a coin hidden under three cups.

"I'll tell you when to stop," their dad added.

They both nodded and started shuffling themselves. They ran round and round like chasing each other's backs until their dad told them to stop. They stood straight, their hands still covering their peckers, and waited for an answer.

"You're Foster," their dad said, pointing to the boy on the right. Then, pointing to his left, he added, "You're Luke."

The twins were flabbergasted. They gazed into each other's green eyes and were asking themselves lots of questions.

"How'd you know?" Foster asked.

"Your foot, Achilles," their dad said, smiling at both boys. "You ran around too much and I saw it."

"You said they won't know!" Luke yelled at his brother angrily.

"Dad cheated!" Foster yelled back.

"It's not fair!" they both yelled at the man.

Their dad chuckled, but it soon stopped when he heard the boys giggling to themselves. He looked at them oddly until the twins took their hands off their peckers at the same time.

"I'm Luke!" the boy, who their father said was Foster (the boy he pointed to on the right), declared.

"And I'm Foster!" the boy on the left said. "See?"

"Lu?" Foster asked, poking his head into the toy chest by the foot of their bed. "Where are you Lu?"

He closed the chest and slumped on the floor. He stared at the big box sadly before pulling his knees to his chest and resting his head on his arms. He was beginning to feel sick already. Luke had disappeared since after breakfast. They weren't even playing hid and seek. His twin brother was just nowhere to be found. He had searched the attic, the kitchen, the dining room, the living room, the bathrooms, their parents' bedroom, the garage, the yard and pretty much covered the whole floor space of their house.

"Fosie!"

Foster brought his head up and search for where his brother called out to him. Fosie, Luke had yelled. It was his brother's nickname for him. Like how he called his brother Lu, no one else was allowed to call him Fosie.

He ran out of their bedroom, went downstairs and called out to Luke, searching for his brother's voice again. He didn't hear it, but he could hear giggling nearby.

"Lu? Where are you?"

"In here!"

Foster turned his head to where the hushed voice came from. It came from the bathroom downstairs, just pass the dining room. He hurried toward it and turned the door handle, but it was locked.

"Lu! Open up!"

"Just a sec, Fosie."

A second passed, then three seconds. Foster couldn't wait that long. Fortunately, the door opened, but only slightly and he was met by Luke's head popping out from behind it. There was a smile in Luke's eyes and he couldn't help but wonder what it was all about.

"Don't tell mum and dad, Fosie."

"Don't tell what?"

Luke opened the door wider and Foster walked in. Luke was still standing behind the door so he couldn't see anything else but Luke's smile.

When Luke finally closed the door, he was mildly surprised to see his brother not wearing anything under his shirt. Well, he couldn't be so sure about that. Perhaps, Luke was still wearing his white briefs and the shirt only hid that well enough.

"Are you wearing anything?" he asked.

"Duh!" Luke chirped and pulled the front of his shirt toward Foster. "I have my shirt on!"

And that was the only thing that Luke was wearing. Foster could finally see his brother's willy sticking out from the under the fabric.

"See it now?" Luke whispered.

"Uh-huh." Foster nodded absently.

"It got bigger!"

Foster looked at his brother's pecker which bounced when his twin bounced. Touch it, his brother told him and so he did. He crouched in front of Luke and held the little package in his little hand. He giggled when Luke giggled tickly.

"See? It's bigger now!"

"How long were you in here?" Foster asked while still fondling Luke's member which was now bigger than it was seconds ago. He was now holding his brother's stiffy.

"Since morning."

"But I didn't see you in here."

"I hid behind the door. You didn't come in, Fosie."

Ah, yes. He didn't come in and search the whole bathroom clean. He was in hurry to cover as much floor space as he could and forgot to check behind the bathroom door.

"And all you did was looking at your willy?"

"Uh-huh!" Luke agreed. "I knew it got bigger so I put my finger on it and it did!"

From what Luke told him, Foster could guess that his twin tried comparing his index finger with his pecker. Lengthwise, that is. He thought of doing the same so he pushed Luke's member up and put the index finger of his other hand beside it. He had measured his and his brother's peckers before, both flaccid and hard. Sure enough, it did grow. A little.

"Wow," he said. "It did get bigger!"

"Yeah! I bet we're the same size now...if I'm not already bigger."

Foster wondered about that. He stood up and pushed his shorts and briefs down. He pulled his shirt up and stared curiously at his little dick. He pulled it forward and put his finger beside it. Naturally, it also got bigger. He fondled with it for a bit and he soon had his own stiffy. He compared it with his finger once more and still got the same result. Bigger.

"Mine is still bigger," he said. "See?"

Luke couldn't believe it. He still couldn't catch up to Foster. His own member may have gotten bigger, but his brother still beat him.

"Let's see," he said as he moved closer to Foster with their privates only inches away from each other.

Both boys bent forward and put their peckers side by side. They both held it forward and their foreskins were already brushing against each one. Although unaware, their stiffies only got harder.

Whereas the tip of Foster's dick touched Luke's skin right where their willies connected to their bodies, Luke failed to do the same. It still had a little gap in between.

"I'm still bigger!" Foster declared exaltedly.

"It's not fair!"

"Don't worry, Lu. It'll only get bigger."

"No, it won't! I'm seewious!"

"Serious." Foster giggled. Luke still can't pronounce the word properly. "I know it will."

"You're not a doctor," argued Luke as he stepped back and pulled his shirt over his privates. He was about to reach for his briefs on the sink when Foster stopped his hand.

"You don't need a doctor to know," Luke said. "But I'll become a doctor and tell you that it'll get bigger."

"A doctor?"

"Uh-huh. I'm gonna be a doctor one day."

Luke giggled and reached for his undies once more. Foster didn't stop him this time. Soon, they were both dressed appropriately and staring at each other's reflection in the mirror.

"Who's Foster?" Luke asked.

Foster chuckled and said, "Who's Luke?"

It was still evident and fairly easy to tell them apart. Not everyone could do it, though. Not everyone could look inside their pants and under their feet. And no one could differentiate the mischief hiding in both their eyes.

"Wanna play doctor?" asked Luke.

"Doctor?"

"Uh-huh. You can be Doctor Fosie."

Foster nodded and they eventually found themselves locked inside their bedroom with Luke lying naked on the bed and waiting for Doctor Fosie to go over his physical exam. Foster took his temperature, examined his eyes and ears and took other measurements before finally proceeding with checking his genitals.

"Doctor Fosie," Luke interrupted. "It hurts right here."

Luke gestured to his pecker, smiling playfully at his brother.

"Can you pull it out for me?" he added.

Foster knew what Luke was talking about. He smiled professionally and held his brother's willy in his hand. He held it up and checked Luke's boysac first before conceding to what Luke's requested.

"Right here?" he asked, his finger settling on the tip of Luke's limp dick.

"Uh-huh."

"Let's see."

He pulled the foreskin back and was greeted by something wet from under it. He nodded thoughtfully and leaned in to take a closer look.

"You need to clean it," he said. "You didn't take a bath, did you?"

Luke shook his head `no'.

"I'll give you one."

"Are doctors s'posed to do that?" Luke asked.

"I dunno," said Foster. "But you really need one, Lu."

"Okay!"

"Lu, what's wrong?"

"Nothing," Luke answered weakly. He could feel his heart palpitating and his vision blurring out Foster's look of concern. "I'm fine."

"You have a fever," Foster said as he put his hand on Luke's forehead. "You're not fine. We'll tell mum, okay?"

"No, really," Luke insisted as he stood up and went for the fridge to get something to drink. "It's nothing."

Foster didn't believe any of it. When he saw how Luke's feet shuffled uneasily toward the fridge, he immediately went to his brother's side just in time to break Luke's fall. He caught his twin under the arms and Luke's head settled on his shoulder. He could feel how short Luke's breathing was and when he helped his brother stand, he felt something hot seeping through the back of his shirt.

He pushed Luke gently away from him and held his shoulders. Luke was bleeding severely. He felt scared and his brother's pale face only doubled his anxiety.

"Lu! What's happening? Are you okay?"

"F-Fosie," Luke stuttered. His knees felt weak and his head started hurting so much. He squinted his eyes, gritted his teeth and moaned loudly. Before he was aware of it, Foster carried him on his back as they hurried to their mother.

It wasn't long after that Luke was diagnosed with cancer. He had a lumbar puncture and it hurt like hell. Foster was right beside him, holding his arms down and hugging him close. He cried on his brother's shirt. He hadn't cried so much before.

"I'm gonna die, won't I?" Luke asked one day.

"No, you're not!" Foster shouted. "I won't let that happen!"

"I have cancer, Fosie. Next thing I know, I'll lose all my hair and I'll d..."

"I said, NO! You'll get better, okay? No twin of mine is gonna leave me behind."

Luke smiled appreciatively at Foster. His brother was indignant on him getting to keep his life. He should also feel determined and hopeful. If that's what Foster wanted to see in him, that's what he'll show.

"You're right," Luke said. "I still need to see you become a doctor, after all."

"And you're going to be a race car driver," Foster said. "An awesome one, too."

"Uh-huh." He sighed and closed his eyes.

He was already becoming immune to the scent of antiseptic inside the hospital. When he was at home, Foster took good care of him and they still got to play their favourite games. Not too much, however.

"I'm hungry," he said.

"I hear there's an ice cream stand by the park," Foster told him. "Want to go down there and buy some?"

"My meds should be here soon. Can you buy one for me?"

Foster nodded and immediately set off to buy a couple of ice cream cones. It was his first time visiting the park. He marvelled at how the place felt so uplifting and how the breeze brushed the leaves almost rhythmically. There was a fountain at the centre of the field and some sort of statue from where the water came out. People were always coming and going, cyclists rode around the area and there were even a group of teenagers practicing their dance routine. It didn't take him long to find the ice cream stand he was looking for. He walked toward it and fell in line behind some kids.

"This isn't strawberry syrup!" some kid way at the front shouted. "It's chili sauce, you creepy old man!"

The old man behind the stand chuckled while the kid walked angrily away. The boy didn't look back and he was amazed to see that the kid still licked his ice cream cone. He only got rid of the chili sauce on top and settled for the vanilla ice cream, from what Foster could see from where he stood.

"Strawberry or chocolate syrup?" the old man asked him when it was his turn.

"Strawberry for me and chocolate for my friend."

"You got it lad," the mad told him. "Come back often and you'll get free sprinkles as well."

"Really?" he chirped.

"Really."

"How `bout chili sauce?"

"What?"

"Chili sauce. You gave it to that boy, right?"

"Oh that was a joke, lad. Don't worry."

"Okay."

Soon enough, Foster became a regular at old man Barry's ice cream stand. He got his free sprinkles and even free ice cream cones. He forgot about that boy who ranted about chili sauce on his ice cream cone. He didn't see that boy again anyway. That was until after more than a year passed and Luke was still receiving his treatment.

He was only supposed to buy the same ice cream cones he bought, but his eyes had drifted toward a weird kid who was pointing his camera to different directions all at once. After he bought his ice cream cones, he decided to look back at the boy and saw the camera pointing toward him. In that split second, he smiled and continued down the path back to the hospital.

"You're right," Luke said. "I still need to see you become a doctor, after all."

"And you're going to be a race car driver," Foster said. "An awesome one, too."

"Uh-huh." He sighed and closed his eyes. "You'll be my doctor, Fosie."

"Huh?"

"You'll find me a cure, won't you?"

"I'll try, but you'll be better way before I become a doctor."

"I don't think so," Luke whispered. "No."

"Why?"

"Coz I want you to be my doctor. You're gonna make me feel better without me losing all my hair and puking stuff all the time."

"We can't be sure `bout that yet," said Foster. "Mum said the meds may work without...uhm...the radiation thingy."

"Yeah. Maybe."

The drugs didn't work, though. Luke started radiotherapy and it was a gruesome task for him. He would vomit several times and he didn't have enough energy to play their favourite games anymore. A couple of months after he started losing his hair, he decided not to go through the same shit again.

"I don't want to!" Luke whined as he was getting ready for his next dose of radiation. "I hate that thing!"

"Luke, sweetheart. It'll make you better, I promise," his mum told him.

"But Fosie will make me better! He'll be a doctor and I'll wait for him to be one. I don't want those meds anymore. I hate them!"

"Please, Lu," Foster pleaded, still trying to get his brother's arms off his. "Me becoming a doctor is still ages away."

"I'll still wait."

"Sweetheart..."

Luke was indignantly reluctant. He kept shaking his head wildly before finally letting go of Foster's arm and running toward the bathroom. When he got inside, he locked the door and slumped to the floor. He hugged his knees and whimpered on his arms.

"Lu, open up!"

He didn't answer. He ignored the shouts coming from outside. He didn't want anyone of them letting him take another dose of radiation.

"I'll be your doctor, Lu. I'll make you feel better, okay?"

"You promise?" he mumbled.

"Yes. I promise."

He wiped his eyes and nose before opening the door and meeting his brother's embrace. He hugged back and his fears were slowly leaving him.

"I'll be the best doctor. I promise you," Foster whispered.

"Okay," he mumbled back.

He kept looking forward to the day when Foster will be his doctor. The radiations kept coming and he was already starting to hate it very much. He reluctantly took his meds and several more infusions, but Foster was still ages away from making him feel better.

Then came one day when he finally decided that it all should stop.

"Lu, you said you'd take your meds."

"You're not my doctor."

"What does that have to do with it?"

"I won't listen to you."

"Damn it, Lu!" Foster cursed, although unintentionally, in front of their mum. "I'll be one when the time comes, okay?"

"I know."

"Then take your meds already!"

"When you're my doctor, I'll take everything you want me to. I'm serious."

Luke finally got the `r' on `serious', but that was beside the point. Foster felt frustrated and watching his brother grow weaker and grunt in pain made each day a living nightmare for him. He still kept on buying their favourite ice cream cones, but sometimes he would think of putting the meds on top of the vanilla and covering it with strawberry syrup. If it was how Luke would start taking his meds again, then he'd gladly ask the ice cream man to have his brother's meds be mixed with the strawberry syrup.