So a while ago I got really bored while sitting in the car for two hours. I accidentally got into some "things" I should say, and I found out something I really didn't want to know.

My first question is- Is it okay for your SO to complain about you to another friend (that's a girl) stating even though he loves you to death that you make him upset some times and tell her that personal business of you two?

Second question- I saw a conversation that went like this.

Him: "Remember that conversation we had earlier the other day?"

Her: "yeah?"

Him: "That if we were both single... Do you think that would happen?"

Her: " I Can't really say."

Now they've been friends during highschool and have been like sister and brother. This convo was probably six months ago, which would be three months into our relationship in the beginning. and they've also dated a very long time ago during there teenage years. Is this conversation something I should worry about..to me it's my SO asking "Hey if you were single and I was single do you think we would become a thing?" Is that even an appropriate thing to say? Although I do know this girl and she is a very nice person, and she's complimented our relationship before. I just don't know what else it could be that they were talking about...but he has also told her every sexual thing we have done together in one conversation. Is that right? Even though this happened long ago I still feel weird..and I didn't want anymore knowing my personal business considering he told me to not tell anyone ours. I don't know how to feel about it ...

ALSO should I confront him? I don't want to tell him I looked through anything..would it be best if I just said I heard some rumors or saw it around? And that wouldn't be lying either, because I've "heard."

I just need help on what to do or if I should even approach it with him? I'm sorry this is so long but advice would be amazing right now.