This could be outing so have namechanged. The back story is I had a one night stand with a guy in my first term of uni, 12 years ago. It was a drunken fling (barely managed to have sex from what I remember), we didn't exchange numbers and just said hello to each other if we saw each other on campus. What I would class as totally no strings.
I got together with my husband, who attended the same uni 5 years ago, we got married last year. I was unaware at the time he was friends with fling guy. It emerged about 3 years ago that they were loosely still in touch and DH went to a bbq at flings house (I genuinely couldn't make it). At the time I did some subtle probing about how much they were in touch and it turned out barely, and it was the first time they'd seen each other in years, and DH suggested that he would probably not see him for another 10 years so I thought there was no reason to tell him.
Last year however we ended up going to another bbq where they were. I didn't say anything as we were having a bad time with family issues at the time. Now some people in his group are trying to include fling (and wife and 2 kids) in more stuff that we do. DH has also brought up inviting them to a bbq later this year.
I feel like I need to tell him about what happened now, especially as he wants to invite him to our home, but also that he will be more included in gatherings in the future. What would people do?!!!
My gut instinct is to tell him, we have a good relationship and I know it would hurt him to find out from someone else, but a small part of me thinks let sleeping dogs lie. I have no idea if dh or anyone else in group knows about the fling and doubt they would let slip if they did.