Looking up pics of increasingly large boobs on the internet and that eventually leading me down various rabbit holes of fat girls, breast expansion, giantess stories, etc and that leading to find pics on dA and whatnot of Very Large Women. I can boil a good chunk of my fetish stuff down to like, an attraction to extremes, excess, taking things too far, "too big" etc. so it all just kind of stemmed from "what if boobs big" and the horizon just kind of expanded from there. The impetus for drawing it... Honestly at the time I don't know what my biggest driving factor was, cuz there was a mercenary element of "I could make money doing this!" and seeing other artists popularity and stuff. Now though it's just cuz I enjoy doing it and I like seeing how far I can push things, as well as the fact that I can make stuff precisely to my own specifications and aesthetic taste.