Wife just won’t let go of the past!

I made the mistake of kissing someone at a party almost ten years ago, and my wife has never let me forget it. She mentions it whenever we fight and constantly brings it up even though she knows it will make me angry. We have the usual ups and downs in our marriage, but if she can’t let go of a mistake I have repeatedly apologised for, I worry that this will end badly. I am already questioning a future with her because her behaviour is bordering on cruelty. She makes me feel like a villain and I can’t manage the guilt that constantly comes up whenever she mentions the incident. I can’t even ask her to stop because it only makes her talk about it again. Is there anything I can do to change this?
If your wife can’t move on from something you have apologised for ten years ago, she is unable to offer you unconditional forgiveness and your relationship will suffer. There can be no evolution without putting this to rest, and her inability to address it may require therapy or a conversation about the root cause. There could be some unresolved insecurity at play, or trauma that makes it difficult for her to see things from your perspective. If you can’t even have a conversation about this, it is a huge red flag because your marriage is not as strong as you imagine it to be. Tell her why this is eroding the possibility of a future together, and hope that this prompts her to acknowledge that this can’t go on. If she refuses to speak to someone about it, and can’t find a way of not mentioning it, things will only get worse.

Is it normal to love someone but also text someone else when there is an emotional crisis? What if I am in love with the other person?
If you aren’t sure about either person, take some time to think about your relationship and why your emotional needs aren’t being met.