The situation: Two years ago there was a new guy in my class at the University who over the years I've become very friendly with. From day one he acted really interested, asking me all kinds of questions. He is a very friendly, energetic, funny guy who it turns out, I have a lot in common with. Same kind of background, same kind of likes and dislikes / humour etc. This formed a bound and I would say that we are friends.
Unfortunately my friend is also pretty handsome and over the course of these two years I started developing romantic feelings for him. At first I just saw him as a friend, we spent a lot of time together at school working on assignments, and during the last school months, last schoolyear, we had to work late and he took me out for a meal, which he payed since I had no money. Afterwards we went for a drink and had a really nice time. It's after this event that I started to see him as more than just a friend, and I started wondering whether he liked me more than a friend too.
Now, the thing is, I've been getting a lot of mixed signals from him. Sometimes I think he might have feelings for me too, looks across the room, always smiling, laughing at my jokes, body language, making plans to see eachther outside of school, but there's one mayor problem with that and with the whole situation. He has a girlfriend. As my feelings have grown stronger for him over the last couple of months, our friendship has gotten complicated. I've been acting weird around him because I have trouble dealing with the fact that I've fallen in love (frankly for the first time in my life) with a great guy who's in a relationship. I don't want to lose him as a friend, but at the same time I'm always wondering what his feelings are for me, and I feel bad for feeling this way about a guy who's already in a committed relationship. I do however wonder why he spents so much time with me? I see him everyday and he usually approaches me, so it's hard for me to ignore him, also I don't want to ignore him, because he's a good friend.
So, my question is: Why do you think he's so friendly with me? And what should I do?