Had an affair - what next

I had an affair over 12 years ago and it involved one sexual encounter but the entire ordeal lasted for about a week. I was friends with this person at work. I had no intentions of leaving my spouse. There wasn’t any alienation. I told my spouse shortly afterwards at the same time I told the 3rd party I couldn’t be around him any longer. Husband and I worked everything out and he wasn’t wanting to leave anyway. Nothing has happened since! Relationship appeared to be loving and everything fine until now.

Now my STBX left a couple of months ago and claims to be unhappy but his reasons don’t make sense. I suspected a female gym friend was involved but didn’t know for sure. I found him dating this very person literally a few days right after leaving and over the last two months. I’ve asked him about it and he denies being with her. So he is hiding this. We have a 7 year old and he wants 50 percent joint custody. The problem is I want to expose a possible affair because he left me for her and he didn’t want to stay and we work through it. If I deposition him and his girlfriend, can he depose me about my affair from 12 years ago? Can my attorney object during questioning due to statue of limiations or anything? And since I make a lot more than he did, I’m sure he will seek alimony. Can courts look back on my affair from 12 years ago and force me to pay alimony even if I can’t prove he had an affair or is there a time limit on this as well?

Thanks for any assistance.

I am not an attorney

My understanding is that if he had an affair, and is the dependent spouse, then he is barred from alimony. And the fact that you reconciled (and subsequently had a child), your previous affair would be a non-issue, especially considering you make more than he does, and you are not looking for alimony. (affair on the part of the person who makes the most money is not something that would affect alimony (as in having to pay more), but an affair on the part of the person seeking alimony would bar him from receiving it.)

He can ask questions in a deposition regarding your previous affair, there is no statue of limitations.
Your affair should not be an issue with respect to alimony since he forgave you long ago and you remained living together as husband and wife thereafter.