Can anyone give me their experience or any statistics on the following:

My wife has admitted to having an affair which is ongoing. The affair partner is a married 48 year old man (my wife is 50). He has 5 kids from high school aged down to twins who are both 7. While my wife has admitted the affair to me, her AP has not to his spouse and as such only sneaks around with my wife when he can get away. He’s asked my wife to give him a few years at home to get some of his kids out of high school before he tells his wife and presumably moves into a public relationship with mine. My wife is emotionally tied to him at the moment and has agreed somewhat to his timeline which I suspect is like 3 years or so but is just a guess.

I know…I’ve pretty much lost my wife and mother of my kids but I’m doing my best to try to save us in various ways. I am hoping to get any thoughts on if this man is not serious and using my wife. I have seen in studies online that it’s not common for a man who is married, not telling his wife about the affair and has this many kids to actually exit his marriage for an affair partner. That’s not to say it doesn’t happen of course but what I read is a guy in his position would have a lot to lose in terms of alimony and child support and my typically choose to repair the marriage or stay where he is then to take the risk of moving on to the affair partner with a serious relationship.