Most Helpful Guy
Wow. Tough spot. Just leave no matter what he says but if you're afraid of physical danger then maybe more covertly would work.
If time is on your side, you could subtly make him less attracted to you. Stop wearing makeup. Fart when he's around. lol Start being interested in or doing things he hates.
complain about his relatives.
Most Helpful Girl
There's no easy way to break up with someone like that. You just have to leave before things get worse, if they haven't already. Don't hesitate to call the police if he does anything drastic, but for now, be brave and leave him.