Guys, how long will you wait to ask a girl out?

lets say you're attracted first, then you become her friend, you have class with her, you become friends first, then you pick on her make jokes, flirt, and when she falls for you too and flirts back, you sort of step back and become more professional. You don't talk much anymore, but you stalk her, and your eyes bloom when you see her, and you seem nervous, the girl is PISSED at you for stepping back and not keeping in touch anymore.and this continues for the next 1.5 years.with the running into each other and staring and his and byes and smiling nervousness. when will you effing ask her out already?

im sick and fed up! and I like him a lot. >.<