Is it just friendship or could it be more?

Hey, Im female and almost 20.

How do I know if my best friend really likes me? I have known him for a while and we spend all of our time together, we are on the same uni course and live in the same flat.

Everyone at uni already thinks we are dating/sleeping together because of the way we act around each other. We are always hugging and laughing. Also when we talk we always look in to each others eyes really deep and we whisper a lot. We also argue like an old married couple.

Not only that but when we are alone together (usually at night) he just strips down to his boxers and we both get into his bed and watch tv till about 2 in the morning. We chat for hours and when we are in his bed we cuddle and he will stroke my hair and my ears and I will stroke his chest and arms. I have also seen him competely naked many times.

Ok this bit might sound weird: if I am sitting on his bed he will jump on top of me with my legs wrapped round his waist and we will hug for ages, he also nibbles on my ears and kisses my neck.

He has a long term girlfriend who he says he is happy with.. what should I do? Do I risk it and make a move or do nothing bcause of the girlfriend?

Is the way we are with each other inappropriate if we are not dating?

HELP!