Guys...how long should a girl make you wait?

How many dates is the right number to wait before sleeping with a guy? I'm a grown woman, not a teenager! So no "wait til it feels right" advice necessary. It always feels right when you fancy someone and haven't had any in a while! Anyway, just wondering how long should a girl make a guy wait because too soon and you're slutty...wait too long and they think you're frigid and they go off you. And should you wait and do it all at once (foreplay too) or does it seems sluttier to take part in other sexual activities with that person before having sex with them (I'm also referring to foreplay)?