You show her that you are better than her ex.
they are just trying to make you jealous and they probably aren't over their ex's yet
liking and loving is 2 different things i wouldn't suggest you to go out with any girl otherwise it will be a replay of your ex and she wouldn't be at fault you would.
First things first: Do not fight him! Avoid a confrontation at all costs! The best way to do this is to wait it out. DON'T make any moves towards her, she's clearly not ready, and it will only provoke her ex. Give her and the ex time. The ex will simmer down, while the girl will slowly but surely get over him. By waiting, you'll get the girl without the fight. Just be careful not to do anything that would provoke the ex and don't try to push the girl in to a relationship she's not quite ready for.
well pooping in a toilet with lolipopos time my ex slapped me over and over and over again
Answer If you no longer have a thing for your present girlfriend, why not be a man, and end it, then you can go out with the other girl.
if your a girl then go to her EX that will make her really mad if your a boy then dont get revenge then you will look like a jerk.
It sounds like he was not over the first girl, and is consciously or subconsciously reliving his prior relationship through another person.
Fake like your going out with another girl then your ex would want you back.
Just Tell Her About Them, Buh Make It Clear That You Dont Have Any Feelings Towards The Ex
You move on, don't try to get him back. Cause he doesn't like you, but another girl.
Do something fun with her to get her mind off of him.
Don't bother with her. She's not ready. Find a different girl.