Is this an innocent encounter, or not?

A guy I dated 15 years ago (for about 5 months) was working (contractually) where I work. We had spoken only once since we dated and that was a couple of years ago when we accidentally ran into each other on the street (and at that time, I told him where I worked during our conversation and it turns out we were both "single" again). At that time, we didn't exchange numbers or information, because we just happened to "bump" into each other.

Well, he came to my office Wednesday and I was surprised! We chatted briefly and I invited him to come back by my office after he finished.

He did, and as we chatted, I told him we should get together for lunch soon and not let so much time go by again...and he looked fantastic, so I was hoping he might still be single and maybe we could hang out again.

I decided I was going to write my cell # down and give it to him before he left...but, as we chatted he asked if I was still single. I said I was, and I said, "You're single, too, right?"

And he looked past me, shuffled his feet, and said, "Well, yeah, but I'm engaged."

I think my jaw dropped, and I can tell you I was disappointed to hear that.

Needless to say, I changed my mind about giving him my cell # ...but he said, "We SHOULD get together for lunch sometime my email address is blahblahblah.com," and he asked for my email address (I hesitated, but gave it to him).

After that, I said I had better get back to work - that it was great seeing him again - and he smiled, opened his arms wide and said, "Give me a hug before I leave."

Now...does this sound innocent on his part? I can't decide if he's prowling, or if he's just trying to be nice to an "old friend". Of course he hasn't emailed me, so I thinking I'm making more of this than I should.