Its not the face you fuck, but the fuck you face!!!! Big girls like that can take the pounding!!!
And the thing is, when you are hitting off a thick or big girl, you getting used to pounding it, so when you are with a smaller girl, that chick is like "whoooooaaaaa!!!!" Because you are used to pounding thick women.
It's kinda like working out with a 50 pound dumbell for months, and then picking up a 15-25 pounder.