This has been field tested over 50 times. Women respond to it in a very predictable way.
Setup: Generally I set up attraction material by using it in response to a rapport-seeking question. I break rapport until the woman tries to seek it, then I break it further with an attraction routine like this. You can also set it up by bringing up the topic of having a boyfriend/girlfriend if she is not seeking rapport.
Her: Do you have a girlfriend? (Rapport-seeking question and display of interest in me)
Me: (With head down, looking sad and shaking my head) No. (Wait a moment, then look up, back to normal/happy look) I have eight girlfriends!
Her: You have eight girlfriends?!?
Me: Yeah, it's pretty cool. They all know each other. They hang out sometimes. It sure keeps me busy though.
Her: Wow, I've never heard of something like that.
Me: Yeah, I know I have a crazy lifestyle.
Her: That's really something.
Me: Hey, you know what, you're really sweet. I've been thinking of getting a ninth girlfriend. Now, I don't usually do this, because we don't really know each other that well, so don't tell anyone about this... but, um... maybe you might want to be my girlfriend?
Her: Sure, but I want to be #1!
Me: You want to be #1? But we just met!
Her: Well, I'll only be your girlfriend if I can be #1.
Me: Wow, tough one. Okay, check this out. Now I really never do this, but just this once, I'm going to do it for you because you're really sweet. I can make you #5 right now. Right off the bat, you're #5. That's kind of a big deal actually.
Her: No way! I want to be #1.
Me: You'll be able to make it to #1 I think, but you're going to have to work your way up. You'll probably have to take me on a few dates, buy me presents, and stuff like that. But I do think you have a good chance. If you really try hard, you can achieve your dreams.
It's been extensively field tested, and many of my students have watched me run this one. The women know it's a joke, and they play along with it. Have fun!