Lying about porn

My husband and I have had multiple conversations where e we both agreed porn was off limits and cheating in our relationship. He doesn’t want me to watch it and vice versa. He is the one that even brought it up. I found out today he’s been lying and watching it basically every morning. This is such a violation of my trust. I’m just so over it at this point in my relationship. He’s allowed to masturbate and do whatever he wants with his body but we have over 500 videos and pictures he could’ve used. Would it be horrible to break up over this? I just feel like e we clearly don’t have the same boundaries/expectations anymore so maybe it’s time to move on. He’s been trying to earn back my trust over stuff he did a long time ago and then he does this. I’m just so tired of his constant lying