Probably far too late for anyone to see this now, but I wondered if you meant something like this...
https://www.wattpad.com/story/704320...rry-fanfiction
https://www.wattpad.com/story/710606...tion-falling-2
https://www.wattpad.com/story/794767...iction-falling
It's not following the plot but it's attempting to keep the same characters and continue them on after the films but with one of them having gained weight that is definitely not the focus of the story but is a recurring theme throughout the three parts. Sounds a similar idea to your Master of Disguise example.