Hell, yes!

Nodding, Matt moved between his sister's spread legs, his cock throbbing in anticipation, her pussy twitching in the same anticipation. His knees stopped between hers, and he stretched himself over her naked body and gasped at the double sensation of his cock pressing against her shaved pussy and the feel of a hard cock pressing against her. One of her hands slipped between them, guiding his cock head against, and then between her labia.

Lily's hand, with Matt's mental guidance, moved up to stroke his face. "Fuck me, dear brother. Take what daddy claimed the night of our 18th birthday."

Matt pushed his hips down, reveling in the double sensation of cock pressing into pussy. They both hissed as he sunk deep, Lily's pussy stretching more than it had to with their dad's smaller cock. He kept pushing, though, until his hips were pressing hard against hers, his chest laying on her breasts, his head over hers. Matt pressed his mouth down on Lily's as his hips raised, her legs wrapping around his ass to pull him back inside. He let his weight down on her thin body, using his weight solely to the movement of his hips, the sensations of both cock and pussy almost too much for him to bear. He could also feel the press of her body on his, and the press of his body on hers, as well as both tongues wrestling with each other inside their mouths.

They kissed passionately, his arms slipping underneath her body, hers wrapping around his back, clinging to each other as if afraid any separation could become permanent. The only part of the siblings to move was Matt's hips as he fucked his sister in a slow, steady pattern. He could feel the excitement growing in Lily, could feel her impending orgasm, which added to his own pleasure.

Then he felt her orgasm, more powerful than anything he had ever felt during his own masturbatory sessions, washing over her body like a flood. The sensation was enough to drive him over the edge, and Matt pressed down as hard as he could, aided by Lily's pulling legs him closer, her legs spreading as far as she could to get his cock as deep inside her as she could as cum exploded from the tip, bathing her cervix in potent sperm.

The two siblings remained glued to each other, all Matt's weight on his sister, all his concentration on the connection of his cock inside her clenching pussy. It was the oddest sensation, feeling his cum spurting into her, not only from the viewpoint of his cock, but the viewpoint of her pussy being filled spurt by spurt. He kept kissing her, wanting the sensation to last, not even caring that either of his parents may look in on Lily and find him balls deep inside his sister. He knew, right then, he was going to have to do this again.