A morbidly obese person who eats nothing but the most unhealthy food, watches TV all day, and has no idea what is really going on in the world around them.
My neighbor is such a cupcake eater, she can barely make it up the stairs to her third floor apartment.
A CupCake Stan is someone who is so sweet and loving towards their bias, they often get offended at the littlest of things towards their bias but they show a lot of love and support.
Eg.
"She's such a cupcake stan"
"She's so sweet and protective"
Refers to the crappy team many Division FBS (I-A) colleges use as a warm-up for their football season and to sell tickets to alumni. Teams that fill up on cupcake teams often get fat and lazy, resulting in a thorough ass-whooping come time for conference games.
Every now and then the cupcake wins, prompting a torrent of lulz on every NCAA internet forum. See Appalachian State vs. Michigan.