Anything I do wrt AP will make them unhappier without a doubt.
Surely this is enough to stop you?
When you go to message him, imagine your kids happiness level plummeting as a result of whatever chain of events that would set off.
They don't even like him, your kids I mean. Even they can see what a nob he is.
My relationship with my husband is really good. But I feel awful about what I did. He didn't deserve it. He did nothing wrong. I think about the consequences of it was discovered or I confessed.
Imagine his face if / when he finds out. A man who deeply loves you and has had done absolutely nothing wrong, has been by your side supportive and kind for the duration of your relationship.
Sorry I know it sounds mean probably but I guess I'm trying to help.
Surely when you go to message this man, picturing your partners face finding out what's happened is enough to stop you?