Not sure how I feel!

A few years back my then boyfriend (now husband) was talking to someone else on Facebook and it was not appropriate. She was an old friend, but the content not ok (not sexual).

I thought we had dealt with it - although I still struggle with feeling a little hurt (she sent me taunting messages so that’s how I found out). It came up in conversation today and it turns out she actually invited him to spend the weekend with her after we announced our engagement (this was before I found out about the messages) I was gobsmacked to be honest as I wonder now if there was more to it than a “few loose compliments she read too much into”

He refuses to talk to me about it as he feels there is nothing new and I need to leave it, but I feel differently. I really don’t know how to feel but it’s eating me up 😢.