I became friends with someone through a friend, who I realised I'd had a one night stand with her partner many years ago. Before they were together. I didn't say anything.
Her partner then started to message me saying I hear you're now friends with X (we were still friends on social media , it was just one night thing but we knew each other before it happened so just kept each other on socials) I said yes I am , she's very nice. Then several times after this he would message me, recalling this one night stand and how amazing he apparently thought it was. I told our mutual friend and asked for advice, we agreed if it happened again I'd tell her, which it didn't.
They have now separated, and the mutual friend told her he had messaged me when she was getting upset about him as she wanted her to know what kind of person he is. So I've now had to tell the poor girl everything and I feel terrible.
Have I been in the wrong not saying anything before?