How can I resolve this social conflict?

I could use a little friendly insight on a situation that’s been eating at me for awhile.

I’m in a very deeply satisfying relationship with my Fiance. We aren’t very social people who have tons of friends, but have recently taken joy in the occasional party outside with our neighbors, one of whom became an actual acquaintance/friend. We took them out to a bar once, even, and have hung out at our places together on many occasions. It’s been nice, light-hearted change of pace every now and again, especially considering we get so lazy and reclusive at times.

I tend to get hit on by a few of the guys at the parties, but never this friend, which I appreciated. This person always seemed more interested in our friendship, and barely paid me any attention in a male-vs-female way. I was relieved by this, and felt basic security in having them around us.

A few nights ago, the man and I were out by our community pool with these people, when I was left alone with this friend for awhile. Everyone there was slightly tipsy, but not drunk enough to be impaired. I was in the pool, swimming about (in a flattering, but not too slutty one-piece bathing suit), and he was sitting outside several feet away. We were having a rather personal conversation about his ex-wife and their situation, and I was offering input, when somehow, the subject of the conversation segued into being about how he is intrigued by me. I didn’t expect it at all, and had all my guards down. He finds me mysterious/alluring, as I tend to be a quiet person and we’ve only actually had a real conversation a few times. I initially stated how surprised I was by this crush, that I didn’t get that impression, but being the nosy, forward person that I am, I began asking questions about it further. Before I knew it, he was regaling me with how “beautiful” and “young” I am, and how I seem to “do whatever I want”, and how “coy” I am. Oh, and the whole while, giving me lovestruck eyes. I’d drop kindly that it’s nice to have a friend we trust, and all, slightly downplaying what we were discussing, but I’d get evil soonafter, and begin making the kid uncomfortable with very direct questions.

Long story short, by the end of the night, my Fiance was on the phone threatening to injure this guy (ahem, tear his throat open). Part of me felt badly, as I could’ve swiftly shut this guy up if I wanted, but I guess I was amused and fascinated by his seemingly spontaneous crush and by extracting information from him. Also, the balls on this guy—for hitting on me, when his own friend is engaged to me. That alone gave me license to prod and to be reasonably evil.

My man ran into him the other night, and he apologized profusely, to the point of embarrassment and annoyance—so I hear, though I wasn’t there. He then, later, got absolutely sh-tfaced drunk, almost fell over, and told my man, “F- you” when he had offered to help the guy up.

The whole saga’s lingered on my mind for days, though, as I feel like we haven’t resolved anything. I still feel really uncomfortable about the conversation we shared. I still don’t know whether his crush is legitimate, and something I need to worry about, or whether it was an admitted mistake. I still don’t know if this person is our trustworthy friend or not, or if that’s history.

How should I go about this? I don’t want to personally phone this guy, or go to his apt. (neighbor), but I wish to speak to him in-person, alone, to decipher the situation better and be very upfront. At the same time, I don’t want to upset my man or make him worry/get jealous.

Any insight/advice?