Author Note: Reposted from AO3. That's a weird thing to say since I feel like it's always the other way around...
Anyway, let's hope that the line breaks work.
Full Summary that got cut off due to character limits:
Sasuke was just a little boy looking at the stars with his older brother. When he asked what the little crusties around Itachi's eyes were Itachi responded with, "Truth or a lie?" And Sasuke replied, "Truth." And Itachi said, "It's matter." And Sasuke asked, "What's matter?" And Itachi said, "What's the matter with you?" And Sasuke just cried because the truth was all he got nowadays. And the truth was not what he wanted to hear.
"Nii-san?" Sauske asked.
"Yes otouto?" Itachi shifted in his spot on the roof to look at his little brother.
"How did the stars get in the sky?" Sasuke pointed a chubby finger to the thousands of stars twinkling in the sky.
"Do you want the truth or a lie?" Itatchi asked back. This was something the brothers did. Whenever Sasuke asked a question Itachi would tell him the truth, a lie, or both.
"A lie and then the truth!"
"Okay," Itachi let a rare smile touch his face. A light breeze blew by and a shiver passed through Sasuke. Itachi scooted a little closer to share his warmth.
"A long time ago the Moon and the Sun were good friends," Itachi began.
"You mean they aren't now?"
"No they still are. But one day," he continued, "the Sun and the Moon got into a huge fight. The Sun was so mad that it asked its son Hikaru to-"
"The Sun's son!" Sasuke giggled.
"Yes the Sun's son. Now let me finish."
"Okay I'll be quiet."
"The Sun asked Hikaru to shoot down the Moon with the fire arrows it provided. Hikaru knew that the fight between the Sun and the Moon was silly but he could not disobey the Sun's orders. So Hikaru shot at the Moon and purposely missed.
"Every evening before the Sun set, the Sun asked Hikaru to report his progress. And every evening Hikaru said the same thing, that the Moon had dodged all the arrows. The Sun would then give Hikaru more arrows to shoot.
"This went on for a long time until finally, the Sun forgot what the argument was even about and ordered Hikaru to stop. The Sun and the Moon reconciled. The arrows Hikaru shot at the Moon are still visible today and they are called stars."
"Why didn't the Moon try to stop the Sun?"
"I don't know. Maybe the Moon was mad at the Sun too and didn't want to bother," Itachi answered.
"Okay now tell me the truth."
"You know the Sun is a star, correct?"
"Yeah!"
"Well all the stars in the sky are just like the Sun but really, really far away..."
"Hey Naruto. Why do you think there are stars in the sky?" Sasuke asked his best friend.
"Well I know the stars up there are the ones I gave you for your birthday," Naruto pointed at the glow-in-the-dark stars Sasuke had taped to the ceiling of his room.
Sasuke rolled his eyes and smirked, "You know what I mean."
"Fine," Naruto laughed. "Stars are in the sky because… of science."
"Science? Is that all you got?" Sasuke tossed a pillow at him from his side of the bed.
Naruto took the pillow and added it to his pile, "Yeah. Science is the reason for everything."
"Is that the truth or a lie?"
"It's the truth! Now let me sleep!"
"Nii-san!" Sasuke yelled as he rushed to the backyard where Itachi was lounging.
"Yes otouto?"
"How am I alive? How are you alive? How is anyone alive? How are people born?" Sasuke spat out when he made it to Itachi's side. His chest rose rapidly as he tried to catch his breath.
Itachi placed a bookmark in his book and closed it. "Are you asking where babies come from?"
Sasuke paused in thought, "I guess I am."
"Truth or a lie?"
"Lie then truth."
"Okay then." Itachi patted the chair next to him and Sasuke gladly took the invitation to sit. "There's a big stork in the sky that watches over all the couples in the world. Sometimes the stork decides that the couple needs a baby."
"What if they don't want children?" Sasuke interrupted.
"The stork doesn't care."
"Oh…"
"Yeah. Well the couple gets a notice in the mail and the mother goes to the baby store to pick out a baby. The baby has a nine-month period where it needs to be kept warm. So the mother stores the baby in the warmest part of her body, her stomach.
"After nine months the mother goes to the hospital to get the baby removed. That's how babies are born. Now for the truth. Do you think you can handle it?"
"Of course I can."
"Well..."
Sasuke was not ready for the truth. The more Itachi talked the more twisted Sasuke's face became. By the end Sasuke's head pounded from his tense muscles.
"That's gross," Sasuke said when Itachi finished.
"That's nature."
"Naruto how are babies made?" Sasuke playfully smacked his boyfriend's arm.
"Is that a hint? We aren't even married," Naruto paused and then laughed into Sasuke's neck, "And we're guys."
"No. It's just a question," Sasuke answered and pushed Naruto's face away.
"Well then. When two people really love each other…" That part was a lie. Love has nothing to do with baby making, but Sasuke let him continue, "…they have sex and a baby may or may not be conceived. Is that a good enough answer?"
"It passes," Sasuke said as he leapt out of bed and headed towards the shower.
"Hey Nii-san?"
"Yes otouto?" his voice was raspy.
"What happens when people die?" Sasuke gave Itachi the cup of water that sat on the side table.
Itachi took a sip. "Truth or a lie?"
"Lie."
"When someone dies their soul turns into a seed, but not one that is planted in dirt. It's then launched into the sky by the tears of their loved ones and planted among the stars."
"What if they don't have any loved ones?"
"You know the times when you feel sad for no reason?"
Sasuke nodded.
"There is a reason. It's for the ones with no one left."
Itachi paused to take another sip of water then continued, "As the tears dry, the seed grows hot and bright and eventually becomes a star itself."
"What about the Sun's son?" Sasuke asked.
"That was a lie remember?"
"Yeah I remember. Can you tell me the truth now?"
"I'm sorry," Itachi's eyes were worn and sad, "but I don't know what happens when people die."
"Then will you get better?" Sasuke tried to ignore the cup shaking in Itachi's hands.
Itachi smiled, "I will not get better."
"Is that the truth or a lie?" Tears warped Sasuke's vision.
"I'm sorry otouto. It's the truth."
"Why do people die Naruto?" Sasuke held the hand of his soul mate.
"Are you alright?"
"Yeah I'm fine," Sasuke squeezed Naruto's hand and he squeezed back.
"Okay then. People die because they can't live forever," he answered.
"Will you and I die one day?"
"Yes."
"Is that the truth or a lie?"
"It's the truth."
"How are you Itachi?" Sasuke asked the cold stone in front of him.
No reply came.
Sasuke set the flowers down. "Are you coming home?"
Silence and that was the truth.