Found Porn In E-Mail..

I was redoing mine and my boyfriends resumes today. I was on his laptop doing them and needing to save them to am email draft (so I could print them out at the library). I went into the drafts and there was multiple porn videos saved from January and February.. I don't consider porn cheating, and I understand that sometimes you just have to masterbate! But my problem is... We never, ever, EVER have sex. Its so rare. Maybe 3 times a month.. I don't think I'd be upset if we were having sex but.. Were not. And I'm incredibly insecure about myself lately (I've gained weight) and he knows that. So why would he make me feel worse by doing that? I don't know. Am I overreacting? What would you do?