In love with my friend

I’m in love with my best friend who has a gf.. I work with him and we had sex with each other while we were in relationships, we talk about doing it again and we can talk for hours about anything and everything. He drives me home sometimes, and I sit with him in his car after work to just talk. I’m truly in love with him and I haven’t felt like this in YEARS. He’s told me things about himself that no body else knows and I’ve done the same. He’s breaking up with his girlfriend soon and I just don’t even know what to do or say. I can tell he’s into me to but I just don’t know how to express my feelings to him.. what do I do? We have spent the night together before and we cuddled and drank and I ended up throwing up, and he just held me all night and held my hair and is so caring towards me. I want to invite him over to spend the night tonight but it just feels so wrong since he still has a girlfriend. What should I do? Should I just invite him over or express my feelings or wait for him to make the move?