Stiles was hit by a wave of disgust—of betrayal and pain and oh god- His heart dropped into his stomach. He was torn. Torn between running as fast as his legs could take him and throwing up right then and there.

He should have known, he really—he reminded himself- he should have, because he was dating the most attractive werewolf to have ever graced the earth with their stupid surly beauty. He really should have figured that a scrawny, geeky teenage idiot wouldn't be enough for him.

That didn't mean it didn't hurt to walk in to Erica straddling his lap kissing him stupid.

"I… uh, oh god." He said turning and running out of the room, tears flooding his eyes.

"Stiles" Derek yelled from the other room. Stiles kept going, shoving his way past Isaac who was stumbling through the front door. "Stiles!"

He made it to his jeep, eyes flooded with tears, vision blurred as he dug through his pockets searching for his keys.

"Stiles" Derek said catching up with him and reaching out to put a hand on his shoulder.

"Get the fuck off me!" he snapped, spinning around, contempt settling in his bloodshot eyes, tears still trailing down his face.

"I know I won't be able to push you off me but unless you want wolvesbane in your cheerios tomorrow morning I would take your hand off of me."

"It wasn't…" Derek sighed pulling his hand back and shoving them in his pockets. "Stiles…"

Stiles rolled his eyes, "my names not going to change no matter how many times you say it." He said running the flannel of his sleeve over his eyes. "You know, I don't really want a reason, I don't care."

He said fishing for his keys in his pocket again, face wet with anger and sadness, but mostly regret.

"You wanna know the funny thing; I knew it was going to happen."

Stiles laughed leaning his back against his jeep, running his hand through his hair. "I knew it was only a matter of time before I wasn't going to be good enough. I mean have you seen me? "

He shook his head silently because this was just- knowing something like this is going to happen doesn't make it hurt any less when it actually does.

"If I was smart, I would have just never started it to begin with—this." Stiles said gesturing between them. "I would have walked away when you kissed me. I would have run, and never looked back. I would have listened any of the million times Jackson reminded me that you're too good for me, I would have found a normal in my league person to date." He said still not meeting Derek's eye.

"But I'm stupid and I deluded myself into thinking they you might actually like me. Hell, that anyone would actually like me."

He stared at the spot where Derek's feet met the rocky pavement; sure he wouldn't be able to say any of this to his face.

"The longer it went on, the more I let myself believe maybe you wouldn't get bored. Maybe you wouldn't realize how annoying I was and leave in the middle of the night. Maybe someone might actually stick around. "

Stiles was beyond caring that his cheeks were wet. That he looked like a sniveling mess. That Derek probably thought he was pathetic.

"Shows how dumb I am huh?" he said laughing darkly.

"Stiles…" Derek said reaching out.

"Don't you fucking touch me!" Stiles bit, taking a shuddering breath. "Please- just don't touch me." Stiles begged because he knew. He knew that even though Derek was an asshole. Even though he just walked in on Derek playing tonsil hockey with someone that was most definitely not himself.

Someone he had viewed as a friend up until very recently, he knew that even though he should be beyond pissed off and taking a key to Derek's car right now. He wasn't, he was sad. He was hurt and all he wanted was to curl up in his bed and be comforted.

Problem was the one he wanted to comfort him was the one doing the hurting. Stiles knew if he let Derek touch him he wasn't going to go through with this. He wouldn't walk away. He would hug Derek and accept any excuse he gave him just so he could stay in his arms forever and he wasn't going to let himself do that.

"It wasn't what it looked like. She…" Derek sighed; he hadn't ever been too great with words. "I was watching TV and I was waiting for you to come home and the next thing I know Erica was all over me and you were crying and I'm pretty sure I broke her leg when I threw her across the room." He said frowning.

Stiles really wished he believed him, he really wished he did, but who would choose him over Erica.

Nobody, that's who,

"Stiles, I don't. I wouldn't cheat on you. We were good…" Derek frowned, "I thought we were good."

"You know this is the longest relationship I've ever had." Derek said running a hand over his hair, he did it when he was nervous now, something he blamed on Stiles because it was definitely something he picked up from the kid. "I could never make it work with anyone else, guys, girls, anyone. I couldn't make myself want them for any longer than a week. I definitely did not plan the future with them."

Stiles leaned his head against the jeep again resisting the urge to hit it against the glass.

"It's been ten months Stiles. It's almost been a year and I still wake up every single morning wishing you were right next to me, and when you're there—they're the best mornings of my life. I can pretend, just for a little while that I can keep you all to myself. That you won't have to go to school and I won't have to go to work. That we can just be us for a little while and god—I want that every day."

Stiles snorted. "You've got a funny way of showing it."

"I didn't kiss her." Derek said taking a step forward, "why the hell would I want her when I have you-look I'm not very good at all of this. I'm not good at talking and you know that. But I love you, Stiles-" he said reaching a hand out before thinking better of it and retracting. If Stiles didn't want him to touch him, well he was going to have to respect that.

He frowned, never breaking eye contact.

"I asked your dad for permission to ask you to move in with me after graduation," he said, voice a little shaky. This was not how he wanted to do this, he had a dinner planned. He was going to ask, not pull it out as a desperate attempt to keep Stiles from breaking up with him. "I'm not going anywhere as long as you'll have me."

Stiles' eyes went wide with shock-"you did…?" he asked slightly dumbfounded.

"I did."

"And he didn't kill you?" he said suspiciously.

"He said you're eighteen and he might not wholeheartedly agree but if it makes you happy he's not going to stop you." Derek said with a shy smile. "So what do you say, move in with me?"

Stiles barreled forward, wrapping his arms around Derek's middle.

"As long as you promise that this will never happen again." He said grinning into Derek's jacket. "I'm serious whatever made her think its okay to kiss my boyfriend, never again."

Derek chuckled, "heat"

"Excuse me" Stiles asked pulling away.

"She's in heat."

"That's a thing?!"He asked laughing; face screwed up in half confusion half amusement. "Since when is that a thing?"

Derek looked confused, "always." He said pinning Stiles against his jeep and pressing his lips to his boyfriends head. "I love you, you know that right?"

He didn't say it much, not out loud, but that was going to change. He was going to tell Stiles 100 times a day if he had to because he needed to understand.

"I love you too." Stiles said with a goofy smile pushing up to kiss Derek sweetly. "Should we go check and see if Erica's okay, you know not forcing everyone into compromising situations?"

Derek laughed, "Boyd just got home. I'm not too sure he's going to mind all that much."

"But she's got Isaac in there" Stiles said laughing, "Scott will kill me if I let his boyfriend get jumped, we've had enough misunderstandings for one day babe." He said with a half-smile.

"All right I suppose I could be persuaded." Derek said leaning down to scoop Stiles off the ground and carry him into the house bridal style.

"I love you." Derek said kissing him with a smile.

"So I've heard." He replied with a smirk. "I love you too sourwolf."