I know this thread is old but I remember making peoples' OCS like Ptyra/Artie/Keirra larger than usual without their permission back then but then months later, I figured it was rude to draw peoples' OCs and/or make them fatter without permission, especially if you aren't sure if they don't like that fetish (I never intended it to be $@xual of course though.).
However, last month, some user on DeviantArt wanted me to draw Hakunaro's OC named Sky and bloat him with water and even earlier, another user wanted me to do 3 artworks of Ptyra (one was her stuck in a tunnel, the other one was her and her herd with big bellies.), but of course, I denied those requests.