Unsure of what to do.

This entire situation is entirely confusing and I'm not quite sure how to proceed.

I moved away for work and during a social event, I met a friend, let's call him "X" over a year ago and when I met him he was dating a girl (who had also come with him to the job). Over the next few months, X and girl had a lot of issues and they eventually broke up. X and I had become good friends throughout the process and he asked me to live with him when his lease was up. I agreed and many months down the line, I am here now.

Here comes the problem. I suppose you could say I am bisexual. I am attracted to both men and women, but do not find a lot of romantic emotional connections with men (although I have not been with a guy before, so I cannot say for sure). Over the course of a few months I began to feel attracted to him and I would like to reason that perhaps it was contact attraction, i.e. seeing him everyday, interacting with him everyday, etc. I would get jealous when he would get all schmoozy with other girls and I found it absolutely infuriating and knew that I had to do something about it. So I told him that I found him attractive (he already knows I am bi) and that I could not explain why I was attracted to him, but that I wanted to stay friends and I would try to get over him. The only thing he said to me during the conversation was "Don't worry about it," I'm not really sure what that means, but I am under the assumption that he just didn't know what to say. He then asked me why I decided to tell him and I said that it was because I was feeling jealous that he was hitting on some other girl. He denied this (aka lied to my face in a moment of sheer vulnerability) but I did not say anything in response because it seemed unproductive. I explained to him about the first time I told a guy that I liked him and that we worked through it and remained friends despite the mild stint of awkwardness. We hugged and I thanked him for being so understanding.

Weeks go by and things go back to normal but I am left wondering wtf "don't worry about it" x100 repetitions means and why he didn't actually say much during our talk and why he didn't choose to follow up the next day with anything. X is a very closed off person, when he broke up with his ex-gf I had to pry out an answer for "how he felt about it." It's very hard to communicate with him sometimes because he just chooses to not say anything, but I know deep down he thinks a lot about everything. Another event with flirting with girls happened and I got a tad jealous, but got over it, but decided to have a chat with him because I cannot seem to get over him. So I decided to talk to him and said that he was really closed off and that I would like to think of him as my best friend (and he said I was his best friend, too), but that if someone asked me what kind of person he was, I would not be able to answer because I honestly couldn't give a lot (not that he's boring or lackluster, just that he is always very PC with his answers and never really tells you anything). He knows this to be true and that he's always sort of had communication problems, but it's also that he doesn't trust people (including me) for whatever reasons (he did not elaborate). Then I said that I had no idea what he meant by "don't worry about it," and I forgot his answer, it was very unmemorable I guess. I finished up by saying that I am having trouble getting over him and that I had to know if he was straight. He told me stories of how girls in the past would all think that he was hitting on them (kind of just how he is) but that I was the first guy to ever tell him anything remotely close to what I did. When I first told him I found him attractive (I did not say like) he made effort to say that he was not interested or that he was straight or turn me down. So when I finally asked him he gave me a very sheepish, "yes" and nothing else. I settled, thinking that it was sufficient to help me move on. I was wrong. We had a tight hug and resumed with our lives for the next few weeks.

Then, we go to a dinner party with some friends. When we return back to the apartment at around 11pm, I am in his room, chatting and he decides to show me pictures from his childhood. This is already sort of a big step for him. As is showing me the pictures from the computer, I move really close to him and look at the screen. Then, he decides to show me his pictures from a trip he took with his father a few years back. I am standing behind him while he is sitting in his desk chair and I wrap my arms around his neck and place my chin on his head. We were in this position until about 4AM and my resting chin was only interrupted by him moving his head so he could look up at my face when he made or a joke or something was funny. During the chin resting, I could tell that he was getting a boner (as was I) and he had to occasionally shift his pant crotch. After 4AM we part ways to sleep. The next day he made no complaints about staying up too late.

Over the next few weeks, I would go into his room to chat, he would want to show me something and I would rest my chin on his head and wrap my arms around his neck. Sometimes he would move to look something up, but he would always return to a position where I could rest my head and arms. He seemed very eager, always, to continue showing me as much stuff as he could to prolong our "hanging out." Resting my chin turned into resting my cheek by his ear, caressing his chest, and massaging him (inside his shirt). Every time we "hung out" in this fashion, he always got a boner and would have to readjust. I would walk into his room as he was watching a video, watch with him for a little bit and then being our "hanging out" and noticed that he always had to hide his boner. He was always so permissive and so receptive to our form of hanging out and it became kind of confusing. We rarely interact outside of the apartment (fine by me) but when we are home we always make an effort to be in each other's company (unless he is chatting vigorously online with probably some other girls), but I would like to say that I am a particularly astute and perceptive person and have good gay/bi/interest-dar. I see how he looks at other guys and other girls (esp the ones he could be interested in) and I see the stark difference between "other guys" and me (not just by the virtue of being his best friend). We recently went on a trip to visit some friends and we had to share a bed for a few nights. When we woke up in the mornings, he would check some websites on his phone and show me something and I would rest my arms and head on his chest and we looked at his phone for some time.

I hope that I am not stupid when I say that he is showing some interest. I have met a lot of tolerant straight men, but I feel that in my situation, most of them would be weirded out if I decided to rest my chin on their heads...ESPECIALLY with the knowledge that I found them attractive. Also, historically, people have said that he is probably gay or asexual because he does not have the same sexual drive and nor does he actively pursue women. His ex gfs have been girls who have shown a lot of interest in him first. I am not sure what to think or what to do. As we speak, I believe he is at this (really ugly) girl's apartment after they had dinner and probably sex (because she has been trying to get in his pants since day 1) <-- (not that I would know because he does not communicate or trust anyone). Deep down I keep telling myself it is hopeless and that nothing will come of it, but it is impossible to not interact with him (because we live together and he is my best friend). It would probably be best to give ourselves some distance so I would have time to get over it, but when he is sending me signals as aforementioned, I cannot help but get my hopes up. I am not sure what to do, I know getting angry for feeling like I have been played is probably not a good idea.

I apologize for the lengthy post.
tl;dr: semi-unrequited interest with "straight" best friend / roommate.