Most Helpful Guy
He is immature. He wants to be back with you because he misses the good parts of what you had and he is not thinking about the reasons which led to your breakup. Of course, if you got back together you would re-experience the good and the bad and it would probably lead to the same outcome.
Stand your ground and go no contact.
Most Helpful Girl
Well I guess it would depend if you were having sex. Then I would say he misses it and hasn't gotten any better offers so wants you back, for now.