Falling in love with my bestfriend from high school

K guys. I'm kinda very emotional about this, so please be kind. There is this guy that was my former bestfriend in high school, we literally cliked and the chemistry was good. A rarely good chemistry, not joking. But we were deep in the friendzone, so I didn't event consider any type of romantic relationship with him. Looking back now, I can see that deep down I really liked him. I don't know why I didn't see it back then, but whatever.

A month ago I got a message from him. He asked if I was going to this party nearby, but since I was busy working I couldn't. At that time I was feeling a little lonely, so I was really flattered by him inviting me, because we hadn't spoke in like 2-3 years. Suddenly I got this thought that he could be something for me.

I thought, that it whole crush was because of my emotional state of mind, and the thing is that he is in a relationship. Which made me think, nope, I can't fall for him when he is not available. But you know, once in love there is no turning back. So after a while, I started to realize there was no hope.

A month after there was another party, and I was hosting a before the party- party. If it makes sense. So I casually ask him if he wanted to come, and in my mind I was hoping that he came without his gf. (Even tho thats wrong) But he was very interested in coming, and first he was supposed to come alone, but two of his friends tagged along.

The reason why I invited him was to test the waters. Because I thought it was all in my head, but things started to happen. No cheating, just things that doesn't belong in the friendzone. The whole night he was very onto me, and very affectionate and he touched and hugged me a lot. Then he was like: "After these years it's not even awkward. Tell me why is that?" and " Why aren't we hanging out more, like we used to?" And then after the big party, me, my bff, his bff, and another friend of his (A guy) , headed back to my place. My bff and his ended up making out, so they went to another room. lol. So left in the living-room it was me, him and the random friend of his.

Then he was like, come and lay down with me. So we ended up cuddling on my couch, so we just talked and laughed and had a very good time. We listened to music, and then we ended up playing a game on my phone. It was not something that you do with regular friends, because it was very intimate and he just cuddled with me. So the random friend wanted to go home, which I get. So he (my crush) was like; I'm sorry but I have to go. And I could tell he didn't want to go home. So he gave me a long hug, and then another hug and then another. It was like he was holding on to me, then he whispered in my ear " I care for you a lot". Then he hugged me tight again and almost kissed me but it didn't happen, thank god. Hence his gf.

I know it's very wrong since he has a girlfriend, but I can't help what I'm feeling. I think that we've always had a thing, but neither of us has realized it. When we were bestfriends in high school it was never a flirtatious tone, like it was now. We didn't even flirt or were affectionate with each other. Just a normal friendship. But now the whole dynamic changed, and I don't know how. Everything feels so easy with him, and everything comes naturally. For me that is very rare, that I find a guy that really makes me feel this. It's hard to explain. And I have never met his gf, all I know is that they have been together for 5 years. He didn't even mention her.

What should I do? I know I should move on, but it is sooo hard. If you read the whole thing, I send you a big hug and thanks.