A while back, there was a girl who liked me, and when I told her I wasn't interested, she let it go for a few months before developing an unhealthy obsession with me disguised as love and ended up treating me like complete crap. That sure was a wild ride.
I also once had this boyfriend who was just a general douche. He got jealous all the time for no reason, tried to control me, kept trying to make me do things I didn't want to, etc etc etc. Now whenever he tries to talk to me, I only humor him because he lets me borrow video games and buys me food sometimes (I don't like it when people spend money on me, but hey, free food). He's not as bad as he was when we were dating, but he's still kind of a jerk and pretty annoying. I tolerate him at this point.