I cheated my girlfriend but I regret it. What should I do?

Johnsy000
So I'm (21M) a big ass fan and my girlfriend (17F) has a pretty big butt. We are having a lot of sex. I love her so much beacuse I thought she has the biggest ass ever. Well recently I saw someone with a bigger ass. I started a conversation with her. Then I asked her out.
So we went to her (25F) house and had sex the whole day. I told my girlfriend I wasn't feeling it that day. But the thing is the new girl is older and her ass probably stopped growing but my girlfriend's ass is still growing bigger and bigger. So what should I do? Act like nothing happpened or tell the truth and promise I'll never do it again?
I cheated my girlfriend but I regret it. What should I do?
13 Opinion