Relationship drama

So me and my boyfriend have been together for a little over two years now. We have a one year old as well. (A little backstory on what's been happening) he's cheated on me in the past multiple times and I've caught him every time. Recently everything's been going way better than before. Although, we only have sex once every two weeks and he and his friends have been sending each other pictures of women's breasts..... I got mad at him and feel like I've been betrayed yet again. Am I wrong for feeling this way?