I don't know that I can offer any helpful advice, other than Trust Your Instinct/ Gut, and Do Whats Right For You in the end.

Granted, my situation was quite different than yours is, as I was never married to this woman, but still. We did give it a go for nearly 3 years. Only to then take a 6 year break (I know, kind of long break tbh, yet its a long story – too long to share here), only to be together for 3 months, with me having to call it quits at the end of the 3rd month (mind you, she still lived under my roof for a number of months after that, which became extremely difficult on me once she openly began seeing, and discussing other guys with me).

But yeah, I was in somewhat the same situation the first time we were together. I ended up having to leave California to find work back in my hometown in Alaska one year. And while I was gone, she not only had relations with a younger guy behind my back, she also started having relations with her much older boss (he was in his 60's, while she was only 23 or 24 at the time).

Instinctively, In my gut, I just knew something wasnt right. And while, like you, I called her out on it, only for her to say I was over reacting, that or he was just trying to be a “fatherly figure in her life” (due to how her relationship with her own dad was strained).

Yet it all came to a head after that New Years Eve (mind you, she went to her bosses business party, while I stayed home taking care of her daughter), when she not only slept over that night, but also when she remembered leaving her vehicles keys back at his place. Where we ended up taking a taxi over to his place to get said keys.

Yet when we arrived he wasn't there, and while she was on the phone with him (mind you, she walked away from me while she was talking to him on the phone), once she hung up the phone and walked back over to me, is when it all became rather quite clear.

She proceeded to tell me that, not only was I right all along (that he wanted to be more to her than just her boss), that if I was still there when he arrived, he was going to beat the ever living crap out of me, and take what he wanted.

This is where I said to heck with this crap, and began walking back to our home (mind you, she picked me up along the way).

Yet once we were got back to our place, being clearly upset at what all had just transpired, I quietly began doing house chorus. Yet bcuz I was noticeable slamming things down along the way, she then proceeded to cuss me out and tell me what a piece of **** I was, that and how I ruined her life (mind you, I was the only one out of her entire family who was there by her side when she was going through cancer, the only one there to do just about everything for her but wipe her ***, as she could hardly even take a bath, much less feed herself. And yet, bcuz I was upset at her having an affair, I ended up being “the bad guy”)...

Despite all that, however, I would encourage you to simply trust your gut here. Not saying she isn't telling the truth now, yet there is also a chance that she isn't. Not saying everyone is bad out there, yet through all my experiences with others, its all made me to be very cautious anymore.