Guilty pleasures😬

I’ve been wanting to masturbate lately, but I feel guilty for pleasuring myself to another man’s body while I’m in a long term relationship. He and I are suuuper open about masturbation, but we have this rule where we don’t tell each other what type of porn we watch, (it makes us insecure). I know masturbating/watching porn isn’t cheating, but I feel guilty when I do! He’s sent me dick pics and videos so I can watch on my own time but it just doesn’t cut it for some reason. I need someone’s opinion, idk how to feel about watching porn anymore.