#serverestorms

One of them is a personal trainer that the other goes to to get into shape. They're not overweight or anything, they're just averagely built, so they want to get shredded like they see in comic books and TV and the like. So they start training, but instead of helping him get super swoll, the trainer starts encouraging him to gain weight. He writes him a rigorous diet plan filled with fattening, sugary foods, encourages him to drink copious alcohol at every opportunity, fixes his protein shakes with weight gain power and appetite stimulants, and convinces him that in order to gain muscles you have to gain weight because the more fat you have the more muscles that fat will convert to. They still do training together, but the trainer only makes him do exercises that will show him how much his swelling body jiggles and shakes where it never had before. In the end, with the other guy so much fatter than he ever had been, with moobs and a double chin and a sagging gut, he gives up and decides the exercise is too much work, and when the trainer suggests that they could still be friends and hang out, he no longer has to hide all his attempts at fattening him up, because now he's doing it al on his own anyway. 🥵

Between Steve and Bucky, I don't know who would be the trainer and who would be the unsuspecting other guy....

Can I interest you in a fic where Steve is a personal trainer and teases the SHIT out of big, getting bigger Bucky when they meet by chance in their apartment building? Bucky would never be caught dead taking the stairs after getting out of the army, but when the elevator breaks...

Or... maybe this other fic where Steve's a personal trainer and Bucky is his childhood best friend, also just out of the military, not looking for training but certainly looking for treats and gaining as a result of it? (Chapter 5 is EXACTLY that workout montage you described with lots of teasing)

BUT WAIT! There's more. There's also a childhood friends to lovers fic with lots of kinky weight gain set around Steve being a personal trainer and Bucky as an administrator at the gym. If you like figuring out feelings through kink, you'll love this