Confused by the attitude of my crash/ coworker- is he avoiding??

I and he have known each other at work for years. Our work requires us to relocate to developing countries every 2-3 years thus we had never worked in the same location. However when he came to my location for business, we worked together for a week or so, and he stayed at my place twice (since there was no decent hotel available). We enjoyed travelling, cooking and talking together (but nothing else happened,,,)

He always indicates all the “signs”; looks bit nervous and fidgets around me, stares at me from the distance, ‘accidentally’ touches me a lot, remembers small details I talked before (which I don’t even remember), looks jealous when he sees me talking to other male colleagues, makes me laugh, asks about my next relocation, becomes talkative when only 2 of us are there etc. When I asked him help for my work or career, he is always there to help me. While he does not initiate texting, he usually replies immediately to my messages.

Last 1 month, I finally became able to work at the same location as him (in a nice developed country). However, he has been super busy with many business travels, we could only have 2 lunches together + occasional small talks when we see each other in the office. In addition, I will have to move to another country soon.

During the lunches, he opened up more than before and shared his personal stories. He also repeatedly (!!) said that he would not be able to come to my new location due to his nationality (he cannot get a visa), asked when I would leave for another country and if I would come back to his location before his next relocation, and said that we have to catch up soon again etc. At work, he also continues to show all the signs mentioned above.

Although he seems to be very confident and a leader-type of a person at work, I sometimes found him being sensitive and shy. As myself being shy, I do not think I have ever clearly shown my feeling toward him. Yet, I think he sensed that I like him.

As my departure approaches (he knows I will leave sometime soon but does not know exactly when), I tried to ask him out for lunch as a colleague. However I feel that he is sort of avoiding me. If so, I do not get the reason… Any thoughts?