How do you know IT'S ON?

I see others who uses context clues to know when woman are attracted and wants said men int heir presence.

Now, I'm not some RSD who can make a list and explains the tricks or hints when such a thing happens. Does anyone have any idea when this happens?

An example would be this. In the 1st girl when he says how MANY, from there on, how doe she know to escalate and it's on?

I know it's not a replacement or an action to take to heart since results vary but it gives me an idea when to escalate and go straight ahead after observing the woman and her intentions.

EDIT: Punctuation.