When someone has become a hogger; when someone has had sex with a fat chick or a fat chick; when someone has gone hogging.
When we were at the bar the other night, Jon started hitting on a fatty. He took her home and had sex with her. He got fat bitched and now he is a hogger.
Surprisingly, "bunch of fat bitches" is not a term used to refer to overweight women in a derogatory manner, although it could be used that way. It is more often used to refer to just about anything in a negative light when the referrer can't think of anything wittier to say. See brainfart.
Doesn't always describe something in the plural sense. (See below).
"This taco tastes like a bunch of fat bitches."
Or;
Person #1: "Look at that bunch of fat bitches!"
Person #2: "..."
Person #2: "Your mom is a bunch of fat bitches."