A/N: I posted this to AO3, almost forgot to post it here! Unbeta'd
This is insane.
The edges of Derek's vision were tinted red as he slammed his fist into the stack of old floorboards piled up in the corner of the newly-renovated den. A loud crack rang through the room as the wood broke.
He wasn't even sure how it started or escalated this time. But of course, he had done something to piss Stiles right the fuck off, so now they were avoiding each other like middle school children, and honestly, haven't they outgrown this stage? They've been together for almost a year, and Derek had really thought he was wrong about his concerns of dating a high school senior. Now he knew that was a pretty valid concern and ALMOST regrets his decision to ask the hyperactive teenager to be with him.
Another board broke under his fist, the wood splintering into his knuckles.
"Stiles, for the love of God. Can't we just move past this?" Derek bellowed into the house as he flexed his fingers to force the splinters out. He knew Stiles could hear him from his position in the upstairs library. He heard a shuffling of feet on carpet, and then a door opening, only to be slammed closed again. Derek winced, his temper flaring dangerously as he squared his shoulders with an angry huff. "Jesus Christ."
He turned toward the stairs, taking them 2 at a time in long strides. He stalked over to the double doors leading to the library, toward the crashing sounds of Stiles' anger. Derek ripped the doors open, growling when the brass handles came off in his hands. Stiles didn't seem to hear him, because he was seated at the far end of the library, pulling down still-packed boxes of books and slamming them down on the floor, muttering under his breath. Really, it almost made Derek's own temper fizzle, seeing how flustered Stiles was- it was just so cute.
Derek was prepared to tell him to stop being a petulant child when Stiles turned, still mumbling, to throw a book onto a nearby table and caught sight of Derek. He froze momentarily before rolling his eyes and turning back to the books.
"Can't even have a little bit of privacy, can I?" He grunted, slamming an old leather-bound book onto the shelf in front of him. Derek just blinked, completely prepared to let Stiles rant as per usual, but that didn't happen. Instead, Stiles sighed, leaning his forehead down on the leather-bound book he'd just shelved. It took Derek less than three seconds to realize Stiles was crying, half of a second for his temper to completely disappear, and another two seconds to cross the entire expanse of library to pull Stiles into his chest.
They stood like that for an unknown amount of time, neither of them moving or saying anything, merely just taking comfort in each other's presence. Derek watched snow fall outside, quiet and soft to match Stiles' sudden mood change. The boy said nothing, made no sounds, and soon the wet warmth of his tears against Derek's sweater stopped.
Stiles lifted his head, eye to eye with Derek now. His bleary eyes held so much emotion: anger, frustration, anxiety, worry, fear- oh. Oh.
"Derek..." he warbled, voice breaking when Derek's hand came up to brush away a stray tear. Derek cooed at him, running his thumb across pouty swollen lips before leaning forward to place a soft kiss there.
That morning, the pack had stumbled right into the crossfire of a rogue werewolf fighting a visiting family of hunters. Derek's own stupidity had caused Stiles to throw himself between a hunter's gun barrel and Derek's chest, and Derek had growled from his lupine form, a low threatening growl that the hunter had mistakenly interpreted as a threat to Stiles. One thing led to another and things got so out of hand that the only solution had been for Derek to trade his life for Stiles' own. Had it not been for Chris Argent stepping in and pulling seniority, Derek would have taken an aconite bullet to the back of the skull- right in front of Stiles.
Derek cradled Stiles' head and placed soft, reassuring kisses all over his face and neck while Stiles composed himself.
"You-" sniff "asshole-" hitched breath "why did you-" sharp exhale "just give up like that."
Derek sighed. "He threatened you, Stiles. He was going to kill you if I didn't. I could smell it on him."
Stiles just sniffled loudly. "I always get threatened. Literally, always. You've never just rolled over like a bitch before."
If Stiles wasn't half delusional from his own paranoia, Derek would've made him pay for that statement. Derek was not a bitch. "Maybe I finally snapped. Every single time you selflessly throw yourself in the line of fire to protect me, a part of my sanity dies. Stiles, I can't risk something happening to you. I don't deserve that kind of heroism."
Stiles just gaped at him. "You absolutely do deserve it." He squeaked, but Derek growled.
"No. I don't- I'm not good at a lot of things, Stiles. I'm not the best Alpha, I don't always know how to help my betas, and I'm a crap boyfriend. NO, I am." He cut off Stiles' protest with a finger to his lips. "But I know I could be better. I'll promise to try to be better, if you promise not to throw yourself into danger so haphazardly from now on." It wasn't much, but it was worth a shot.
Stiles sighed, eyeing Derek as he weighed the words. "Fine," he finally agreed, slumping forward to bury his nose in Derek's neck. It made Derek's heart flutter warmly. "Haphazardly being the operative word. I have no qualms about doing so strategically, however."
Derek rolled his eyes and wrapped his arms tighter around Stiles.
Somehow, this awkward teenager had found his way into Derek's heart, and Derek had absolutely no idea what to do with it. So he just held him in the silence of the warm library while snow fell quietly outside.