Here is the thing. You are going to have to take the conversation sexual and you are also going to need to really amp up the kino to get the same night lay. If you are confident and go sexual, and she is accepting of this. Meaning she doesn't actively say something about you shouldn't be talking like that or that's gross then she has mentally accepted some things with you.
You don't have to worry about bouncing so much. Still you do need to begin to isolate. Get her isolated from the group so you too can talk and her group is cool with you two being alone for a bit. Then return her to the group. This establishes trust and rapport with the group subconciously so when you go to the bedroom or wherever....
The other thing you need to figure out is logistics. You need to figure out what their plans are for the night. You need to know who she came with and what she has going on the next day. I usually ask these later into the conversation and break them up. If she has somewhere to be at 6am it's hard to close that night. If she drove all her friends it's going to be tough as well. If you see where I'm going with the logistics here.
Final thing, is that if you aren't vibing with a set or a particular girl this isn't the time to plow on. If it's not vibing it's best to just move on to one that you do "feel" the tension growing. The enemy will be the 30 minutes to hour you spend with the girl that doesn't go anywhere, and you miss out by the end of the night.
And as far as conversation goes. You can talk about anything. Just demonstrate pre-selection, and other DHV spikes and again keep some sexual overtones in the conversation. Think like a horny middle schooler that laughs everytime someone mentions the word "penis" but toned down a touch. You get the idea though.
Hope all this helps man,
Jon
PS> You might check this out I wrote it a little while back, but it has all this and some.
http://jsmooth26.blogspot.com/2009/02/s ... t-lay.html