TBaby/Jason/Smith/Watching Trevor and Alice
As soon as you're out of the way, Trevor scrambles on top of his sister and buries his cock into her spunky cunny. "Hey!" She says as she realises what's going on. Trevor doesn't care and you can see his bare bum going up and down as he fucks her.
As you watch, you realise two things. First, that they were lying when they said they'd only done it once before, and second, that watching them is the most erotic thing you've ever seen and your cock is rapidly recovering.
It doesn't take long before Trevor is gasping with his climax and you can't help noticing that Alice is more or less just laying there and letting him get on with it. As soon as he's finished Trevor rolls off and lays down beside his sister panting with his exertion. "It'd be more fun for Alice if you took your time," you say.
Trevor looks as if he's about to cry. "It's not fair, your cock's bigger than mine," he says.