Emily plays catch

Peter starts grunting that seems to signal he is going to cum. You keep rubbing his cock to encourage it. You are about to look up at Emily to see her reaction but before you can she swoops in and, to your surprise, places her lips on the tip of her brother's prick.

This stimulation is enough to set him off, Peter lurches out of his chair and, with a yell, pushes his cock deep into his sister's mouth. You can feel his ejaculate throb underneath your fist as it surges into her. He thrusts two more times and you swear you can see her throat bulge as he goes really deep.

He falls back to his seat, and before he can open his eyes, Emily has already returned to her standing position.

That doesn't stop Peter for going bright red when he sees her standing there...