I think you've gotta get over this. Unless you suspect something is still going on between Jasmine and him, it's time to grow up and get over it. He's basically your brother in law now, and it's not right or fair for you to demand he not be at family functions because you can't get over your own hang ups. It's no fault of Jasmine's or his that circumstances have brought them back into the same picture, so suck it up, stop being a pussy, pull your tampon out, man up and accept his presence.

^^Know that I say all this with respect to you and totally understanding how you feel, as I've had some girls ex's around and I hated it. But you've just got to get over it so that family functions don't suck.