My H goes through SAD every winter, there really was no way for me to know that this winter was any different. He never expressed how he was feeling and I thought he would come out of his funk in the spring like he always did not run off and have an affair. We were still having sex a few times a week.
My idea was not to shame him but like I said I could no longer keep his secrets. I can't imagine my kids finding out a few months down the road the real reason for our separation from someone else. I do feel they deserved to know the truth.
Yes, it probably did drive him farther into the arms of the OW. There's not a lot I can do about that now.
See your own lawyer before you do anything. If you have proof of the affair, things might be very different than you H thinks they will turn out - depending on the laws in your state. Don't believe what he says - he is only acting in his own best interest, not yours. My H even tried to block my access to our marital home when he was having an affair. You can't trust him to be truthful or have any allegiance to you at all at this time.
I'm sorry about your kids. Your H's claim that they weren't mature enough to 'understand' is as ridiculous as my H's reason for why he didn't tell me about the EA (before it went to a PA): He figured I would flip out.
M 16 yrs, WH62, P54 3 adult blended kids EA 11/13, BD1 6/14 PA fall 14, BD2 2/15 Piecing 2015, BD3 12/15 Separated 4/16 WH moved OW in 5/16 Divorced 6/15/17