The OM is a person that has been in our life as my W's trainer for probably a couple of years. My kids know him in this role. My guess is that the A has been going on for a couple of months. I do not believe that the kids have been "exposed." It is not unusual for them to go to his place. In fact, they all went there on new years eve for a party and there were other people there. It is highly unlikely that my children are ever alone with him. His wife is frequently there but she does work outside the home so there are times when she may be gone. However, there are almost always going to be other people there. My kids are 13 and 14. I had a concern that they were being used to baby sit his younger kids when his wife was at work so that the OM and my W could have a rendezvous. But I have no evidence or reason to think that has occurred other than my mind wandering and thinking of the worst. I have not noticed any odd or new behavior from my kids.
There is absolutely, 100% an A going on. There is no doubt about that. The proof is absolute.
I don't think my kids are being actively harmed by being in the OM's presence. I just think its inappropriate for my wife to be having an A while still living in our house and involving our children in her activities with him.
Me: 48 y/o W: 47 y/o Together: > 20 yrs BD: Dec '15, then S 2nd BD: Mar '16, then I filed for D April '16: started piecing