Should I tell him?

Please read all to understand.

Hello guys I have the most wonderful husband and great father to our child! Although he has cheated before not sure if I should still feel the need to tell him everything although I’m scared of his reaction that he’ll probably wanna do something to upset me just to be even for example say “yeah well my cousins have send me there girlfriends too”. My cousin send me on Snapchat a video of her boyfriends but it was a very quick video like 2 seconds but I don’t want to tell him exactly what she sent.. when I heard a another buss I said it’s just “Jessica sending me very inappropriate videos that she shouldn’t be sending me” it was on Snapchat and if I knew it was that I wouldn’t have opened it and I would be very upset if I knew his guy cousin send him a video of his girls ass 😡 I JUST FEEL GUILTY IS THAT NORMAL? What do I do?