Love affair

I'm in love with someone I shouldn't be and I don't know what to do about it. This man is my supervisor at work and he's married and has 2 kids, we went to a work party and he kissed me and after that we kept meeting up, going for days out and having sex like he wasn't even married. He told his wife about the affair and they wanted to sort their marriage out, but I see him all the time because we obviously work together and he still messages me every single day without fail and talks about us being together, we decided to stop speaking outside of work but neither of us could do it. He wants to transfer to another shop but if he moves he knows his wife won't so I have no idea what to do