BOYFRIEND FLIRTING WITH HIS EX'S HELP!?

Okay so my boyfriend's name is Matt. Me & Matt have been together for about 4 months now and I love it. If I was sad seeing him would just brighten everything and he's just got the hottest body! Whenever were together public or private he always tells me I'm his forever and that he loves me. I can't stand not being around him. But we've been having MIVE fights because he still talks to his ex's. Okay I get talking and staying friends with ex's i understand that and I'm mostly fine with it. But he doesn't just talk he flirts and leads them on. He goes out and stuff with them and doesn't tell me. Who the f*ck knows if they aren't in a room having . I love him so much and today the same thing happened like every other fight. I was angry with him so i wasn't talking to him. Then he came to my house & said exact words" Baby, your my forever ,your the only girl for me i love you. And then I said if you mean that why do you flirt with your ex's! & he doesn't see that he leads them on or he's just acting stupid. Then I started crying and told him to leave. He wiped the tear drop from my cheek and kissed me. This always happens because when he kisses me its like nothing ever happened and the only thing that matters is me and him. After he kisses me im like under his curse ahhhhh! Help!