You turned your sister on with a vibrator, but who's gonna fuck her to orgasm?

The deal was a blowjob, but you can fuck your brother too, why not?

My parents are away, and after cognac it doesn't hurt as much in the ass

Money? I'd rather suck your dick! But know that blackmailing your sister is not good

Sister was breaking down over a blowjob, but ended up asking for a dick herself