What do I tell this guy or do about him?

I have a boyfriend (my age). But there is this guy in one of my cles who is 3 years older and he won't leave me alone. When I first started to hang with the guy i'm dating (as friends) the older guy got jealous and would say stuff like "why don't you go hang with your new man??" "Wheres that other guy you like?" and was being rude. Once we started dating he kept glaring at us, and saying rude things to me so I avoided him and ignored him. He acted like we had been dating or something and i hurt him. A few days ago he apologized (seemed serious) so i said okay its fine. Now he's flirting and being creepy and trying to be "friends" with my boyfriend. What do I tell him? My boyfriend is kind of annoyed but doesn't think about it much. It just pisses me off because how was I suppose to know he liked me if he never asked me out?