What's the deal? Ignored FB message but befriended me anyway?

[miniaturespy656]

I saw a former college mate, I didn't know him personally but knew of him as he dated one of my roommates... Fast forward ten years later and I see him at a charity event and he was actually being awarded that night. I stopped him for a quick pow wow and he seemed engaged but then stated he would return to finish our conversation after he made his rounds with photo ops and whatnot. He never did, but I didn't take it personal, it was business, however when leaving the event he was extremely engaged with another pretty woman, whom I knew had nothing to do with the function. Ego is a little bruised by now, and I continue to leave. Few weeks later I decided to take initiative and remind him of our encounter and left my contact info so that we'd link up (hinted platonically btw) on FB, we have a lot of mutual friends so I thought I wouldn't appear like a creepy stalker. He read it, didn't reply but requested to be friends on FB. Weeks go by and still nothing? What's the deal??