This could sound a little odd;
How about a file that makes the male listener thing he's getting a blow job by the sex of his choice, but instead of blowing up like Violet in the Wonka factory, his muscles and genitals expand till he becomes immobile. Then his only way of deflating is to orgasm, maybe by the person inflating him getting on his tool and riding him to that orgasm causing the other to inflate and maybe even pop as they orgasm............
Then stick a little bug in there that makes them think it's really happening to them when they get a BJ in real life :wink:
It's not too nuts, is it?