Unsure

My husband just started working 2 months ago. And everything is going great. One day I get on his laptop and see his Facebook open. Now see. There has been issues in the past with him messaging different women and his ex. Through Facebook and text message and other sites. So yes I went to his messages . And usually he deletes everything. But anyway. He was messaging this girl whom is my sisters friends sister. And she works at the same place as him. In the messages it just says from the girl, are you driving to work today? And can I catch a ride with you. Or can I catch a ride home with you. Like for a few weeks I think it was. And he never mentioned to me how he was giving her a ride almost every day. Only had mentioned giving 2 male coworkers rides to work. I just don't know why he felt he shouldn't tell me. And then I discovered he made like a separate Facebook just to add one girl who also works at the same place. I confronted him on this. And he says. He's allowed to have friends. He can give rides to whoever he wants. And that he wouldnt do anything. And for the profile he claims to not know what I was talking about. I don't know what to do. This has been going on for years. I don't feel like I can keep doing this. He just says he did nothing wrong. There has been so much more . But I forgave him. So I kind of think that he feels no matter what he does. I will initially get mad and then he's ok and can keep doing that.