Why does he do it, im pretty sure he doesn't want me back so why
Most Helpful Guy
He's an immature control freak that wants what he no longer has. He feels a sense of ownership over you, and even though he broke up with you, he doesn't like the thought of other men having what he had.
He sounds like a real jerk off, and it might be a good idea to avoid going clubbing at the same spots he frequents. It's a shame you have to do that, but it's best to just try and avoid him, as he's going to run off anyone interested in you that's wanting to hang out. Or, the person you're with might end up kicking his head into oblivion, which would serve him right.
But, it's best to just keep your distance and find other places to enjoy your nights out. And if he doesn't stop and you feel threatened in any way, then talk to the authorities and see what your options are, because he could be dangerous; especially if he's been drinking or is on any kind of drug.