Does this guy like me and what should I do?

So i started high school this year and I like a guy in my form. I'm in his classes for form, Computing, RE, History, Geog, Music and Drama but the only class when I'm actually near him is computing. When he see's me he goes bright red, but acts completely normal. When our geog teacher is late we wait outside the classroom and he edges right up to me leaning on me, smiles and his fingers just about touches mine.Even when my brother hurt himself in PE and went to hospital, he acted really sympathetic to me and hugged me quickly when he heard. I notice him staring at me during classes. We don't really talk unless it's about our computing work. The thing is, I'm not sure if he's teasing me, or just being nice because I don't think a guy like him would go for someone like me- I'm a bit of a nerd, I'm down right ugly- acne, bushy long hair, tall.. etc etc. Not that he just goes for looks, but I'm scared that he won't like me because of it. I'm nice to everyone, and I help him with work often. I don't want to ask him out because I'm shy and it'll seem desperate and knowing the idiots at my school, the word will spread quickly and if he says no, then that'll make matters even worse. He seemed a bit annoyed when his enemy asked me out (God knows why he asked ME!) and sticks up for me all the time.BTW at school for year 7's we're only allowed mascara and a bit of foundation so can't make much of a good impression. Sorry this was kinda long.

Thanks in advance people :-D