They've been seeing each other for almost a year.
She knew from the get go that he was married. I tried to talk her out of it at the time but she was adamant that they had a "connection."
This guy is older than her, they work in same office and he is also her senior.
I don't know what to do. She's my friend but I also know his wife to some extent. If it was me, I'd want to know (obviously!) But, I don't want to betray my friend.
Wwyd?