My ex is messin wit my head helpppp now?

me and my ex broke up like 2 months ago and right when we broke up he got with another girl and till this day he still gets at me telling me i am the one he's suppose to be with and if i get back with him he'd leave this new girl but if he really loved me wouldn't he try to make it work instead of bringin another girl into it i say whyd u ask her out then he's like some things cant be expained like wtf i dnt get it what is he doing helppppp