I made a very bad mistake a few years ago and I truly regret it and feel very badly. There's no way to change the past, but I really wish I didn't do it. I've tried to have a great relationship with the person I wronged to make up for it. The problem is that if I apologize to the person it will ruin our relationship (and we now have an excellent relationship). While I feel very badly, I think ruining the relationship would just make it even worse. The person doesn't know about the sin. What should I do?