Does my ex bf jealous?

he cheated on me b4,i broke up w/him.he wants me back but i wont let him.he has another new gf again,but keeps texting me,he's cheating her to me,i ignore him,change my number..then he got my number and text me and wants to be friend but i can't i still have feeling to him and he has his gf.and i said i have bf and were seeing tommorrow hes a japanese guy.we text and he said hes happy for me and hes happy now(new gf).we end the text by saying goodluck. then he text me things like i cheated on him b4 w/this japaneses guy.bcoz b4 this guy calling me when wer still 2gether,were just friends(japanese guy)long ago.then he saying bad things to me.then i say bad things to him and to his gf too.we really had a long fight that day.that ended in saying profanity.i off cp,bcoz i dnt want to read his text anymore.and i cant control myself saying bad things too.why this happened?why he act like this?