Before asking someone you're seeing to be exclusive? Has it depended on a number of dates for you? How far apart the dates were? I just had a really awesome 4th date with the girl I'm seeing last night and things are going awesome. Nothing is official yet but I'll be seeing her again at the end of the week. By then it'll have been 5 dates over the course of a couple weeks and I'm really feelin it, so I'm thinking of asking her then.