wait...i don't get it.

i never understood that joke, you know that fat mama joke--

-"yo mam's so fat-- when she sits around the house, she sits around the house."

i still don't get it. unless yo ma is like clifford the big red dog's mama. but if she was that big she would break the house, not ooze around it. i don't get it & i've pretended for too long.