[n4tntly_cnfusd]

So I'm a senior in college and have a boyfriend. Recently (like no more than a month ago) I partnered with a guy in class to prepare a required presentation for our class. This was the first time I had ever talked to him and we met only two times to put our speech together. After we got the presentation over with, I would occasionally see him around campus and would exchange a hello and goodbye. We exchanged a few text messages that were class related afterward, and then eventually we hung out for the first time as friends since we got along well. We grabbed some food and he suggested watching a movie (comedy). I saw nothing wrong by it, so I was like sure. I was seated a distance away from him, when at one point during the movie, I felt his arm slide behind my back pulling me in. I didn't know what to do, as I had never been in such a situation, so probably the worst mistake I made was waiting till the film end to tell him that I had a boyfriend, before anything else happened. Before then I had not mentioned directly that I had a boyfriend, since the first words out of my mouth to a person I haven't been friends with very long aren't "hey, i have a bf..." OK, "did I ask?" Get me? And to be honest, I was sure he assumed something of the like since I wear a ring that was a gift from my boyfriend on my engagement finger and that tends to always be one of the first things I get asked about- "are you married/engaged?" I realize now that maybe I should have said something immediately when I felt his arm, but I'll admit that I was in shock and really didn't want to make the rest of the movie awkward for the both of us. I didn't act on it, you could say I almost just stayed frozen. When I told him after the movie that I had a boyfriend, he seemed caught by surprise and it took him a few seconds to respond. He said it was fine and that he wasn't like most guys so it wasn't going to be awkward between us. I then offered to leave to avoid making him anymore uncomfortable. Before I left though, he was still cool enough to give me a book to read. The next time I saw him in school, I was on my way to class (the one we have together) and I saw him ahead. I noticed that instead of him using the entrance to the building we normally do since it's the closest access to the classroom, he took a longer route to the opposite side of the building. The entire semester he would always have a quick smoke just before class right outside this entrance (the closest), and now, nearly the end of the semester (coincidently the first time I'd be seeing him again), he's opting for another entrance and smoking area? Ok, so I thought maybe I'm just thinking of it way too hard, so I brushed off the thought that maybe he was trying to avoid me; after all, he did say it would't be awkward. The next day I began reading the book he let me borrow. It was really good! So I sent him a text telling him exactly that. He never replied. Come the day of class again, I noticed him smoking on the opposite side of the building again, which kind of now makes me believe that he's definitely avoiding me. But why? I know I made the mistake of waiting too long to say something, but was what I did really that bad that now we can't be friends anymore? Or at least grown ups about the situation? Its really bugging me to know that he's acting this way. Guys, what is your perspective?