I may be falling for a stranger?

there is one person in my college with whom i've never spoken to, though i did have photography cl with him one semester.. he is everything that i look for in a partner, he is tender, intelligent, modest, quiet/mysterious, even his style..i haven't liked anyone this much for years..and now whenever i see him in campus, my heart skips a beat.. im too shy to approach him and besides, im easy to read so even if i did talk to him he would find out about my feelings easily and i don't want that. but even if i wasn't any of those things, i think he has a girlfriend and i would be stupid to even think about getting involved with someone who is already involved.. shortly im in a sucky situation, i can't stop liking him and can't do anything about it either.. what should i do? have u ever been in similar situation?