I registered just to post on this topic.  Let go of that “Once a cheater, always a cheater” thing. You’re a human being. You are subject to growth, change; you can be 10/10 if you let it happen, because after all we’ve control over our actions. Your friend might see you as 9/10 – you can’t control that, but you can influence how your partner sees you.

Trust me, I know how it is, because I am a cheater myself, and I’ve tortured myself over this. It’s not always possible to understand why. Hormones, long distance, a person who reminds you of someone else – it’s multi-variable calculus  which rules we don’t really understand, and I don’t think that’s average people’s job – leave it to scientists and psychologists. And yeah, it hurts our moral muscles, which we don’t realize we have at the time. But dwelling on this issue won’t help either.

It doesn’t happen in an instant, but try to realize that your past became a fact. Not a variable process which is now. Past is a fact. And when someone mentions cheating, remember that it’s not your doing; those are actions and story of other people, and you have your own story. At least be kind to yourself, and moderate the drinking.