Sebastian's eyes locked with Peter's over the curve of his uncle's shoulder, his breath hitching at the desperate, challenging look in those dark eyes. His cock throbbed painfully against his sweatpants, a wet spot spreading where he had been leaking steadily since he first pulled those panties down.
"Oh, I'm gonna," Sebastian breathed out, his voice cracking with how badly he wanted it. He looked down at where his spit had made Peter's hole shiny and slick, his fingers trembling as he brought them up. "I'm gonna make you squirt so hard, Uncle Petey. Gonna be just as good as Dad, maybe even better."
He circled Peter's puffy rim with one thick finger, marveling at how it twitched and sucked at him like it was hungry. Sebastian bit his lower lip, his brow furrowing with concentration as he pushed forward, feeling that tight heat envelop his digit up to the first knuckle.
"Fuck, you're tight," he slurred, wiggling his finger experimentally and watching Peter's back arch. "Is this the spot? Is this where Dad used to poke you?"
He crooked his finger, searching blindly for that bump he had heard about in locker room talk, his other hand spreading Peter's cheek wider so he could watch his finger disappear inside. When Peter let out a sharp cry and his thighs trembled, Sebastian knew he had found it.
"Oh, there it is," Sebastian said, his voice dripping with triumphant arousal. He pushed in a second finger alongside the first, groaning at how Peter's hole stretched around him, how the lace strained against Peter's heavy balls. "God, Uncle Petey, you look so hot like this. Your pussy's sucking my fingers so good."
He began to thrust his fingers in and out, clumsy and eager, his wrist twisting as he tried to remember what felt good when he did it to himself. The wet sounds filled the room, mixing with Peter's whines and Sebastian's own heavy breathing.
"Tell me if I'm doing it right," Sebastian begged, his free hand reaching around to palm Peter's trapped cocklet through the soaked lace. "I really wanna see you cum, Uncle Petey. I'm gonna finger you until you squirt," Sebastian promised. "Gonna show you I'm just as good. Maybe I'll do it even better than Dad did. Would you like that? Would you like if I made you cum harder?"