The Diaper Genie

WARNING: Adult content! This book contains depictions of forced diapering and using of those diapers, spankings, and various other humiliations, both public and private.

When a genie who likes to mess with humans hears a college freshman wish that she could go back to the time that her mother took care of everything for her, he decides to grant her wish in a way she definitely doesn't want. But instead of turning her into an actual baby, he changes reality so that everyone her age is still treated as one, except for the addition of some "grown-up" activities.