Liking someone with a girlfriend

Hello everyone! So basically a few years ago, I met a guy while I was put. He was very sweet and we chatted online loads but never went on a date because I was healing from a previous break up.
Eventually, a year or so later we went on a date, when I was feeling ready to move on. He explained he did like me but he was moving to a city far from where we live and didn't know if it would work out long distance.
I agreed but we still skyped and text everyday, after he moved.
One day he eventually revealed he had met someone where he lived and didn't feel it was going to work out with us living so far away. I agreed this was probably for the best.
However.
His new interest took the opportunity to look through his phone and saw messages between me and him. She instantly saw me as a threat and asked he not speak to me anymore, which he agreed to do.
I made it clear I was upset we could no longer be friends but agreed if that's what he wanted then fair enough.

Since then over the last couple of years, if he is ever back in town visiting and I see him in our local bar he will come over and speak to me. The last time I saw him we both agreed we still liked each other but he explained he lived with her now and it was going to be complicated to get out of that situation.
One of his friends has also mentioned he still likes me but said he could never hurt his girlfriend.
We've never been physically intimate and obviously have never kissed whilst he's been with his girlfriend.

I can't stop thinking about him at the moment, it's crazy. I don't really know what to do or think of this situation?