So I was at a club two weeks ago and yesterday. Similar situations happened.

Two weeks ago: Group of three were dancing two girls and one guy. Went to the girl asked to dance she said yes. We danced, talked, danced. Pretty hot dancing. She excalated slightly I did the same....she said she would be right back....walked over to her two friends who now sitting somewhere. Walked by with the girl directly to me and then walked away....didnt see her again.

Yesterday: Saw two girls one was dancing with a big dude. went up the other one asked to dance she said sure. Dancing talking dancing talking. This time we werent grinding and IM not the best dancer so I like the talking. Anyhow, her friend pulled her away. Again she made a point to say we'll be back twice...this time I stood around for 90 seconds and then left.
In scenerario two is that just the obstacle? And in scenario one is that just escalating two fast without enough game?

Women always do this. You should try and escalate quicker. And try get her number before she disappears on you.