Keith sat at the dinner table with Shiro and Adam. He took a bite of his spaghetti.
"How was your day?" Adam asked.
"Good." Keith said.
"Did you get into any fights?"
"No."
"That's good. I'm proud of you, buddy."
"Thanks."

Keith wasn't speaking much. No one was suspicious, because Keith never spoke much. But the reason Keith wasn't talking much was a different reason today. He had a secret.

"Thirty dollars," He said to Lance.
"Dude, that's so much!" Lance complained, but he handed Keith the money. In exchange, Keith gave Lance the photos. Photos of Shiro.

They had been doing this for a while. Keith would take pictures of Shiro and sell them to Lance. He also sold details about Shiro's life for Lance's fanfics. That's right. Lance wrote erotic, self insert, Shiro fanfic.

"Wow. This one is good," Lance looked at a picture. It was of Shiro's calf muscles. "How did you get this?"
"I spend my holiday breaks with Shiro and Adam. I just hide in their laundry basket with a camera. Adam is onto me, but that's only because he was there when I was convincing Shiro to take off his shirt. Shiro is oblivious as heck. I'm all like, 'Shiro, I need to take a picture of your midriff.'  And Shiro's like, 'oh Keith, I'm so glad you've found a wholesome hobby like photography' and Adam's like 'nope! Not doing that!'"
"Nice. We'll meet here the same time next week, same time."
Keith shook Lance's hand. "See you then."

*Many years later*
"Mrs. McClain, do you have any toothpaste?" Shiro asked.
"Yes, of course, dear. I think there's some in Lance's room. You can go take some, I'm sure he won't mind."

Shiro opened Lance's door. His mouth fell open in shock. "What. The. Quiznack."
Inside was a full scale model of Shiro. On the walls, there were pictures taped up if Shiro's body parts. Lance had a Shiro body pillow.
So that's what Keith was doing with those pictures, Shiro thought, before closing the door and going back downstairs. This explains so much.