single man mentality?

I recently found out on Facebook that my SO followed a half naked woman who pits pics of her in lingerie and dancing videos. When I confronted him about it, he told me that he knows it's inappropriate but the comments are hilarious. Yet when I looked I didn't see any comments that were funny. Awhile back I found out that he follows an amateur porn star on snapchat and had a shit ton of porn videos, pictures, and screenshots saved to his phone. When I asked him about it he said it's because he liked certain videos, etc. this man can make up excuses within the drop of a hat. And it frustrates me. He also was having snapchat conversations with a girl he once was sexually involved with whom was married. I told him I was not okay with it and said he deleted her. But my whole thing is if he's looking at these girls and most likely getting off by them then where does that leave me? I'm not trying to control what he does but it's almost as if he just doesn't think. He just does. Like he has a single man mentality and is selfish. I just don't know what to do anymore. I love him to death but man sometimes he just doesn't think!