BananaYellow and TheChandler have summer up all you need to know.
I could have a bit of sympathy with you if this was an ex boyfriend, and circumstances had meant that you ended up not staying together eg one of you moving away for a job and you couldn't maintain a long distance relationship etc
But in my view, real love always finds a way anyway. My cousin went abroad for work just after she had met someone (who she already knew well through work). I wondered whether they would manage to keep things going seeing as they were the other side of the world from each other and do you know what, they did. They managed it and she was away for 3 years. You only have to see them together to know that they are each other's "the one". She had had boyfriends before who she wasn't even bothered keeping up a relationship with when they were living in the same town
So the fact that you didnt manage to get together with him when he was single speaks volumes. Also talk of you "playing it cool". People who REALLY want to be with someone don't play teenage games. They put their cards on the table and see what happens.
An old colleague of DH's phoned him up when we were first married. We had moved away and his mum had foolishly passed on our new phone number when she rang his mum's house (I think that was where he was living when he worked with the ex-colleague and she got his mum's number from work files.)
Well, Luckily DH had already told me about her having a crush on him before we'd got together but she wasn't his type. Cos I certainly would have wondered who this strange woman was ringing him up out of the blue and it could have caused trouble for us. As it was I was cringing for her as DH queried Her about how she had got his number and why on earth she was ringing all these years later )they hadn't even been proper friends, only worked together). Then he told her not to ring again and put the phone down.
To be honest she came across as a sad, slightly deranged stalker and We both imagined her to be sitting crying at the end of the phone, drunk, after she'd put the phone down, realising what a mistake she'd made in ringing. Not to mention wasting years mooning over the fantasy that was she and him in her head.
Please don't let that be you.