Am I with the right person?

I can only imagine how awful it must of been to hear him say his ex gfs name! I would be gutted! Its a tough situation, i mean it could of been a genuine mistake, was he with his ex a long time? Have you just came out and asked him straight up if he has been seeing his ex? If so and he said no, then theres not alot else you can do. Apart from this incident, is there any other reason hes given you that he may have cheated? Have you got any proof? And what is your gut feeling? Cos if you genuinely believe he has cheated, but haven't got any hard evidence, then it might just be you being insecure, i mean i know him calling her name cant of helped matters, but you either have 2 choices. 1) end it if you cant trust him, and dont believe him, or 2) Put it behind you and try and forget about it. You have got to think about your son at the end of the day, is this gonna make him suffer, if you 2 are gonna be arguing about it?