I hate replying here but I will anyway: Talk about it openly, if he gets furious, leave him.
It takes time to built trust but only suspicion, not evidence to break it.
Something is wrong. Talk to your man about it, honesty is the key.
http://www.blackagenda.com/images/cyber/malcolm-01.jpg "It doesn't mean that I advocate violence, but at the same time, I am not against using violence in self-defense. I don't call it violence when it's self-defense, I call it intelligence."