I'm a male in great shape, I'd love to do a roleplay with another male or a female (or both) who are really overweight, perhaps morbidly so. After making a rude comment about your weight you get revenge on me by finding a way to capture me and transfer your fat to me (along with any other unwanted attributes). You turn the tables and laugh and fat shame me while you're in really good shape now.
Also if anyone has any stories along these lines please share with me!