More than likely those large women weren't so large a couple years ago when they met but then the women decided to get fat like a lot of women who are on the virge of being fat do. And by the time she was fat it was too late and the rings were in place and his pleas went unheard into the soft pillow he used to muffle his sobbing... she's not fat damnit she's just big bo... oh who am I kidding.
Alot of it also prolly has to do with comfort for overweight guys. They just dont think they can get the skinny hot girls so they lower their expectations.
There are more reasons why these kinds of things can happen but talking about them are just making me depressed.