My boyfriends masterbating...

My boyfriends masterbating makes me uncomfortable and really sad. He does it when I’m at home too. I feel like crap because I feel like I’m not good enough. And it bugs me that he’s probably thinking of and looking at someone else while he’s doing it. I feel really insecure about my body because I gave birth 5 months ago. And while I was pregnant he was looking at other naked women on Snapchat. What do I do 😭