How could he be my x and hang with her

well my x boy friend we never tslk he all ways hang out with this girl name mary and I think he still got fillens 4 her he hang with her and it makes me jalise of thtb and he say he dont like her but I think he loves her alot and soo wat me and him broke up

Correction he's your ex , I'm sorry but you can't control him he's free he's not dating you anymore. What you could do now is become his friend or his enemy. So what he's hanging out with another girl let him. Why don't you go have fun and hit on someone and date them?