If he is cheating on his wife, with you, then NO, you can't trust him anymore then his wife can trust him. I don't mean to sound harsh, but I will never understand why women believe that a man, who is willing to cheat on his wife in order to be with them, is worth having. One of two things is going to happen. He will either string you along for months, or even years, by promising to leave his wife, OR, he WILL leave his wife for you, only to cheat on you later on down the road. I had this discussion with my best friend, after she slept with another woman's husband. He left his wife and two year old daughter, and married her......and then, two years later, he left her and their one year old son, for another woman he is now married to.

I am sorry you are pregnant with this man's child because it will make things more difficult for you, but this is not a relationship you need to be in.