Props on the dancefloor spasms and all that jazz
when a chick proximites on the dancefloor she's subtly suggesting that she wants you to approach her in some way or another...(even though this may not be 100% accurate, just believe it is. It will get you approaching more confidently consistently...remember, always have the mindset that your the dogs bullox, your shit hot, and women wanna fuck you).
when she drifts away from a guy and closer to you, you've just hit the dancefloor 'pussy' jackpot. She wants you and you better dive in there and catch that fish like a pro! From this point forth, its pretty simple...escalation, escalation, escalation. By that, I mean ramp up the kino and get her where she wants to be...HORNY AND WET. She'll love you for escalating, and in most cases will reciprocate the kino. When she does, put your hand behind her hair, gently hold the back of her neck...and move in slowly for the kiss. If you wanna spot whether she's ready to kiss you or not - look for lip licking / lip biting, if she allows you to gently caress her ass then she's reached a hightened state of arousal...at this point she'll usually accept the kiss close 85% of the time!
When the 'cock block' tried to bail her chick out of the interaction, you needed to immediately throw value at the 'cock blocker' to disarm her bitch shield and revert her attention to you. Dont give 'excuses' the time to creep into your brain and baffle your logical thought. Act fast.

Hope it didnt waffle on too long, now go get'em!!