Derek hadn't expected Stiles to take his whole length, and so it was with surprised pleasure that he let out a small gasp, his fingers curling tight in the boy's hair. "Stiles--" he panted.
He pulled back, giving the boy a chance to recover, before sliding deep again. He repeated the motion, selfishly seeking his release. "Going to come," he warned, his voice rough, breathless. "Going to paint your face with my come."
The werewolf released the boy's hair and used his hand, slick with saliva, pumping until the first stream hit Stiles' lips. He kept moving, line after line landing on the boy's face, until he had milked his release, and took a step back.