I admit to NOTHING!!! My heart is pure as the fresh snow!!!
But a FRIEND OF MINE could have MAYBE recommended some weird stuff like "Lil' Sister Got SUPER-SIZED" by Gorgon or "The Kiss of Muscle Growth (Sandy-Path)" by ScriptBoy. There may have been some more, but those came to mind first 😅 Not looking specially for sibling-stuff, but I take no offense in it if the story is good.