I do not own the characters of Teen Wolf. I only own this idea.
Derek grabbed a fistful of Stile's shirt and pulled him into the bathroom with him, shutting and locking the door behind him. "Dude, what are you doing?", asked Stiles as he looked up at the bigger teen, who seemed to have gotten paler by the minute. "What do you want, Stiles?", asked Derek as he leaned against the counter, putting all of his weight onto one of his arms. "I asked you something first. Are you sick or something?", asked Stiles as he shook out of the teen's grasp. "Think about that question again.", replied the wolf as he looked over at him in annoyance. "Right. Right. Just answer my first question, what are you doing?", asked the smaller teen again as he looked over at the wolf. "Nothing that concerns you, Stiles. Just leave.", ordered Derek as he gave the teen a light shove to the shoulder.
"Come on, let me into that mind of yours. What are you doing?", begged Stiles as he was backed out of the room. The wolf shut the door in the smaller teen's face, hearing a low 'rude' from him when the door shut. I'm not letting anybody in. Derek walked back over to the toilet and bent over with one hand pushing hard on his stomach, the other sliding two fingers down his throat. The door swung open again just as he removed his fingers and let his body lurch forward as he vomited. There wasn't a single chance of him stopping now, so he repeated the gesture, shoving his fingers down farther as his body lurched again. Derek spit out the remainder and a little blood before he flushed away the evidence, walking over to the sink he washed his hands clean and rinsed out his mouth. The wolf looked over to see a shocked looking Stiles standing in the doorway again.
"P-Pet-!", started Stiles as he looked towards the stairs, being silenced when the older of the two slapped a hand over his mouth. "Shut up. I'm going to uncover your mouth now, do not say a word.", ordered Derek as he uncovered his mouth. "Peter!", screamed out the smaller teen as he ran away from the wolf, quickly making his way downstairs. "fuck.", cursed Derek under his breath as he chased to teen down the stairs and through the living room, grabbing a fistful of his shirt when they reached the kitchen. "What's the matter, Stiles? Is everything alright? Or did you find another mouse again?", asked Peter as he grinned over at the smaller teen. "That was not a mouse, it was a rat!", said Stiles in defense. He was about to continue when the Alpha's hand came down on his mouth again, stopping him from saying anything more. "Everything is fine, Peter, and there's no mice.", said Derek as he half used Stiles to keep himself propped up.
"So why are you covering his mouth?", asked the teen's Uncle as he looked over at him with raised eyebrows. "Cause he has a big mouth that says things that don't need to be said. Be quiet.", the wolf hissed in his ear before he took his hand off of his mouth. "Everything is fine, Peter. Just a little bit of rough housing with your nephew.", said Stiles as he glared over at the Alpha. "Be careful, Stiles. Don't hurt him, Derek, he's human.", ordered Peter as he walked out the back door to join the pack who were getting ready a morning run. "What the hell, Derek?! Peter needs to know what's going on!", asked Stiles as he looked over at the wolf, suddenly feeling the added weight on his side. "Nothing is going on, Stiles! Peter doesn't need to know about anything!", replied Derek as he forced himself away from the smaller teen, now using the counter to keep himself up.
"Something is obviously wrong, you're making yourself throw up!", snapped Stiles as he placed a hand on the teen's shoulder. He could feel the wolf shaking under his touch and he could feel his temperature rising as his skin got even paler than before. "Get. Back. Stiles.", muttered Derek as he felt his eyes close and heard a roaring in his ears. "Derek, what are you? Derek? Can you hear me? Peter! Peter get in here!", screamed Stiles as he quickly tried to support the collapsing wolf. Derek's legs buckled under him as his eyes rolled back and his body shook, he collapsed to the ground at the smaller teen's feet. "What happened, Stiles?", asked Peter as he came running back into the house with the pack following closely behind him. "I dont know, he just like collapsed.", explained Stiles as he looked down at the Alpha.
Peter knelt down beside his nephew and checked his pulse before placing a hand on his forehead to guess his temperature. "We need to take him to Deaton. Derek's heart is racing a skipping beats, which is what might have caused this. Get your Jeep, Stiles.", ordered the former Alpha as he gently picked up his still unconscious nephew and cradled him to his chest. "Is he okay?", asked Isaac as he looked over at Peter with worry filled eyes. "I'm not sure, kid. But Deaton will know what's going on and he'll know what to do.", replied the oldest man as he carried the wolf out to the Jeep and gently layed him down on the back seats. "Do you know where you're going?", asked Peter as he slid into the passenger side. "All too well.", replied Stiles as he slid behind the wheel and started up the Jeep.