An American pussy is a pussy that has very small pussy lips -or "labia minora"...
If the legs aren't wide open the pussy looks like a straight line and nothing hangs outside(Just like a young undeveloped one, we used to touch before the high school years.)...
Usually, for the full effect it has to be hairless.
Also, american pussies stay prettier over time, and don't become as saggy as big lipped pussies do...

What a woman is said to have when she has succeeded in getting a wealthy man to pay her bills or provide for her. Her pussy/game/body/ass/face is so good, he's willing to pay her bills or throw her some cash on top of whatever kind of relationship they're having.

Refers to American Express (Amex), a credit card used mostly by rich people. Its upper tiers are exclusive, with Black being available by personal invitation only.