I have absolutely no problem with opening girls. I can walk up to a group of 2-3 girls, say something witty, and keep the conversation going for a while. But I have no idea how to close. Sometimes I'll just outright ask for the number and I usually get it, but I never get replies.

So I have the first half of the interaction down pat, but not the second. Everything I've tried hasn't worked out. What's the way to go about it?