37 weeks emotional

I know this may seem TMI but I am very emotional. I have been with my boyfriend for many many years and we are finally Having a child after a couple of miscarriages. We have always been honest with each other (have trust issues because of past) and we love each other very much. I don't like having sex since I am so big, but I still help him out. Today he was in the shower and I went in to use the bathroom and caught him masterbaiting. Has anyone else caught their partner doing this and feel really upset by it or am I over reacting? I already feel insecure and he tried to lied about it but I saw him doing it. I saw that he has been looking at porn too! Ugh!