Please help me, what should I do?

This guy who I've been dating has an ex-gf who calls me and sends me facebook messages all the time. It has gotten to be pretty frustrating since all the calls are about how she wants to get back with him. When I told the guy Im dating what happened, he flatly said that his ex would never do such a thing. I'm going to be seeing him in two more days and he says that he will show me some sort of "proof" that it never was his ex. Should I wait for the two days to see the evidence, or should I just stop talking to him now itself (especially how without knowing anything he said to begin with that his ex would never do such a thing). I feel like I have been undermined and that my feelings havent been taken into consideration. When I tell him that he just says, let me just talk to u in person in two days.