I want to move on

I have this one co-worker of mine on whom I had a huge crush. Sometime after we start talking I realise that he do have feelings for me too. The problem was he was already in a committed relationship. We still used to work to gather and chat. He started showing more and more interest in me by taking me out for Lunches, bringing me gifts whenever he goes on a business trip or vacation. My other coworker also told me that he acts very differently around me and that all of them had a feeling that something was going on between us. I was happy and sad at the same time. Happy because I really liked him, but sad because I knew this was wrong and we would never be together.

The worst part is he got married to his gf 6 months back. I was shattered and as a normal reaction I started keeping my distance from him. I can't completely cut him off because we work in the same team and I have to interact with him on a daily basis. I thought that this was the end of it and I will be able to forget it after some time. But to my dismay, he continued being that special person to me. He still chat with me, go to Lunches with me, bring gifts to me. He doesn't like it whenever I ask anything about his marriage or wife.

I really do not want to ruin our friendship but I want to move on from him. The fact that I still feel for him hurts me a lot. What should I do?