I'm with freestyler...never do that stuff at school. I know at 15 that seems the real logical way to do it, but trust me...outside of school, neutral environment. Fantastic.
But...maybe you're too old for the ol' "will you go out with me". Maybe you should find a way to turn "will you go out with me" into a conversation about you both, and the positives and great feelings you're having around one another and see where it goes from there. Just a thought.
Ad Astra Per Aspera