What should i do? bf trouble (sorry its long)?

so my bf and i have been going out for a little over a year and 1/2. he had a ex which they dated for 2 years and when we had been dating for like a month he cheated on me with her. well i didnt realize this. i though he had broken up with me then dated her for like a week then asked me to go back out with him about 2 weeks later. well we did kinda a double date about a month ago and on the car ride home it came up that he had cheated on me with her and thats why he broke up with me. i told him i didnt want him seeing her anymore. well then yesterday he was texting her and that brought up me thinking this morning that he had hung out with her about a half dozen times sence we have been going out (before i knew he had cheated) and how dare he hang out with the person he cheated on me with i was really pissed of and told him that and he said i love you and i dont even think about girls like that anymore and about 98% of what i talk about every day is you and we hang out every single day and that he ditches his friends for me and that how he had told her last week that he couldnt see her anymore (but he should have said this before i even found out is what i think when we started going back out he should have told her that he didnt want to see her anymore and that he was with me) ((i should tell him that)) well anyway he doesnt feel guilty for hanging out with her those other times because i guess hes madly in love with me. and he fells that he should be able to text her to ask her how shes doing. i just dont know what to do i dont want him to have anything to do with her and i think i have the right because of what happened. what should i say to him or do you think hes right. i just need help im so lost :( i want to cry