I am sexually attracted to a guy that I refused to sleep with over a year ago because I was in the state of mind where I wanted a relationship (and he didn’t- he is the kind of guy better off by himself). I kind of regretted my decision and showed him that I’m available but he didn’t even answer me and found someone else (he has a biiig ego).

I got over it but it took some time because I had some self-confidence issues and a mild depression at the time. Now I’m at a point in my life where I’m much better and capable of having affairs without emotional involvement (mostly bc I know that at least with him, we just want different things from life, I have nothing to expect from him ever).

BUT he is STILL seeing that girl (although he remained the same, doesn’t want anything too serious) so he doesn’t lack sex in his life. We are colleagues and I remained with a curiosity regarding him. I was thinking to be straightforward and just ask him (instead of thinking and wondering about it) but he already treated me bad then and I would feel bad as we see each other almost every day. However I would like some answer.

I asked
-what if I tell him that I want to have sex with him? 37.2.3 to 61
-if he’s physically attracted to me 7.2 to 2

I’m not so good at reading. From the 37 I get the idea that I shouldn’t pursue him, to remain in my place. I don’t know what the relating hex 61 is saying.

Hexagram 7.2 talks about being in the center of the army (maybe meaning that he has confidence in himself?)

I sometimes feel that he knows he could have me but 1.he has a way too big ego 2.he is satisfied with that girl but I still wonder how he would react bc I also feel that the curiosity remained for both of us.

I think you're interpretation is on the right track.

I think 7.2 shows that the leader of 'the self' is in the center and the defences surrounded it, so you're likely to meet defences first before you get to the leader. And moving to 2, taking away the only yang line, it does feel like things are switched off.

I can see how 7.2 > 2 also describes your approach to him that you've written in your post.

61, your inner truth that you want to have sex with him, but is that really the inner truth here because from your text in capitals there seems to be some conflict for you about how he is seeing another girl. I wonder what extra information that conflicted part of you has to give about whether what you want is sex without emotional involvement. I like 61, with its enclosing yang lines, as a visual representation of emotionally involved sex.

In my humble opinion sex never happens without emotions, sure you can detach yourself from them, but they still occur. Also in my opinion, sex is better when the participants are openly emotionally involved (not disguising it from themselves or the other).

37 is the family that is your 'self' and taking care of it, no need to throw yourself away.
line 2, you've not gotten what you want but something is there to feed you // alternatively, nothing has happened, go home, cook a great meal
Line 3 Take this seriously, if you detach parts of yourself away simply to join with someone sexually because they are not wanting emotional involvement, that is going to tear you part.

I would also look at 37.2.3 > 61 as to how the dynamics of your family as you grew up are informing you as to your options in romance and relationship. That's real food for thought.

Playing hard to get, push pull dynamics, chasing someone who doesn't want the same things as you do, often point to psychological patterns, that can be changed with support.

I like to think of it like, if you order an uber and they arrive but say you can't get in the car, would you keep trying to order that driver? would you pay them? I would get a refund through the app, and go find one that wants to take me where I want to go.

I never had issues in my family that can be related to this problem, I really had (and still have) great parents and friends that are mature and supportive.
I know that maybe sex without any feelings doesn’t exist, but regarding this guy I can’t say I like him very much as a person and we will take different paths in life (different countries etc) so I really feel there is no room for something serious.
I did asked him to meet and he responded positively (but then nothing).
I know I had my insecurities because of that girl because for a period of time I felt I wasn’t enough (for him or anybody for that matter). It was a tough period but everybody has those sometimes.