Why do ex bfs get so jelous?

A lot of men are very inconsiderate when it comes to girls’ feeling and emotions. I’m a guy by the way. My girlfriend and I sort of have the same situation right now. Her long time friend (and short time boyfriend) feels the need to tell her that he still likes her from time to time and her stares at us when we’re together. Assume in your situation that the ex boyfriend is jealous that your current boyfriend is able to stay with you when he was not. That burns guys from the inside out and causes them to act foolishly. I suggest- and I will tell my girlfriend this as well- that you tell him again. tell him that this is disrespectful to you, your boyfriend and your relationship as a whole and your are not comfortable with him doing this any longer. tell him that is he cares about you at all he would move on,get out of this pit of self-pity and accept the fact that you’ve moved on;you are happy now and that you deserve your happiness. If he doesn’t leave after that-it may be time to block his number and remove him from your life. I hope it won’t come to that though. but the first thing should help :)