"Ready already?" Derek smiled against Stiles' skin. With his free hand, he reached around, finding the boy's erection, hard and straining, dripping with need. "But I've just started with you," he whispered, nosing behind the boy's ear.
He fumbled with the ring, sliding it back up, off the teenager's erection, because it would be cruel to deny him at this point. No, he wouldn't make the boy hold out. Not this time.
This time, he'd fuck the human until he came twice. Maybe three times, depending on how long Derek's resolve held out. Then, when Stiles had shattered, when he'd been utterly destroyed--then he would take his own pleasure.
"Come on, Stiles," he urged. "Come on this rubber cock." He stroked the boy's erection roughly, and shoved the vibrator deeper.