Stiles Stilinski + Derek Hale

my best friend's brother

A/N: Hello guys! I hope you are safe and well. Here's another pretty long AU. I really hope you enjoy it.

I've been reading your comments and some of them make me laugh so much. Please continue to leave comments! I really love them. 

Scott knew that his brother had a crush on Stiles.

Well, he didn't actually figure it out on his own. His older sister, Laura, cued him in while she was giving him a ride to late-night lacrosse practice.

("If I hear Derek talk about Stiles's 'cute little moles' one more time, I think I'm going to throw myself off a bridge," Laura growled. "Wait, why would Derek think Stiles has cute moles?" Scott responded.)

What was even more unfortunate was the fact that Scott also knew that Stiles had a crush on Derek.

("Dude, I know that I've said this before, but your brother has a nice ass," Stiles commented while sipping on cola and staring at Derek's butt as he put dishes back in the cabinet. "STILES!" Scott shouted, immediately slamming his hands over his own ears.)

During the few weekends where Derek was home from college, Scott tried to spend as much time as he could with him, considering the rest of the year his household was 75% female. While Laura wasn't technically living there anymore, she was there practically all the time to hang out with Cora and their mom. Girl time, or something.

On one of such weekends, Scott came home from Allison's and dumped his backpack by the front door before climbing up the stairs to Derek's room.

"Derek! I'm home! I bought Taco Bell on the way back because Mom said-"

He shoved Derek's door open only to see his best friend straddling his older brother's hips, one of his hands down the front of Derek's jeans.

"Jesus Christ!" Scott shouted while falling backward out of the room. He tried to grab at the door frame to stabilize himself.

"Scott!" Stiles cried, shoving himself off of Derek. He yanked his hand out from Derek's jeans, "I thought you were supposed to be at Allison's until 8." He glared at Derek who shrugged in defense, "That's what he told me when I texted him."

"That's your only concern?!" Scott cried, the bags of Taco Bell dropped outside of the doorframe, "I'm trying to erase the visual of my best friend's hand shoved down my brother's pants!" He gagged.

Stiles blushed and grabbed the nearest t-shirt to pull over his head. Despite this, the blue shirt he'd chosen left little to the imagination, as several dark hickeys poked out from the top of the collar.

"You'd have to be kidding yourself if you didn't think this would happen. I mean, I've been talking about how hot your brother is since we were fourteen."

Scott gagged again, "Can we PLEASE not talk about how hot my step-brother is? It's making me uncomfortable."

Stiles seemed to take this as a challenge, as he opened his mouth to respond with, "Well, we can talk instead about the fact that Derek does this with his tongue when-"

Scott shrieked and covered his ears with the palms of his hands, "NO!"

Stiles burst into a fit of laughter while Derek wrapped his arms around his waist from behind and propped his chin on Stiles's shoulder. Stiles let out a small breath and leaned back into the hold.

The front door opened and slammed shut, "SCOTT!" Cora cried from the first floor, "Mom said you bought Taco Bell!"

Scott backed up towards the stairwell, still shaken up, before screaming down them, "I'm up here!"