The chick is used to being treated this way. The impotent husband lost her at cards. That's why they've been pulling her like a bitch all day long. And the harder the stake, the harder they drive it inside. Only the pussy is already so used to the new masters, to the abundance of milk - that she does not want to go back.
Latina knows how to convince the stud to choose her for the lead role in the movie. Letting him test his asshole was the move of a horse. And it worked!