More of a WWYD I suppose. Have namechanged.
I went out with ex for 4 years. We met and lived in my hometown for most of that time, but moved to his hometown for 5 months before we split up and I moved back home with DS. He is DS's father. When we moved to his hometown, I was befriended by a friend of the family, who is also a mum and I think was grateful to have another mum around to socialise with. She forced herself on me a bit at first, but we soon became good friends and saw each other most days. Ex never seemed to like her much, said she was interfering and nosy but I got on well with her.When ex and I split, she was visibly upset that I was leaving and has remained in contact ever since. We talk a few times a week and see each other when I go to visit family in her town. We've been good friends for 3 years now.
This week I found out through a mutual friend that she had a brief relationship with ex a few years ago (about 12 if my maths is right!), and it was a sexual relationship. She has never mentioned anything of the kind to me and I'm sure would be mortified if she knew that I knew. (It is definitely true - when I asked, 2 other mutual friends confirmed. They had assumed I knew. It is common knowledge but because I am not from there, I was unaware.)
Ex and I are over, 100% and I would not take him back for anything. Plus she was before me. So it's not jealousy I'm feeling. But I feel a bit weird about it! We usually discuss everything and I feel like she's kept this from me. Almost like our friendship is based on a lie!
WWYD? Would you mention it or try and forget you ever found out, and say nothing?