dapperdiaper

I'm looking for a story I read a while back and would like to read again. The premise was that a teenage girl was helping a neighbor with babysitting her toddler daughter, and was getting so into playing with the baby that the neighbor drew her into a conversation where the teen revealed that she wished she could go back to being a baby. The neighbor agreed to let her spend the weekend there wearing diapers and being a baby alongside the toddler, and everything was fine until the teen's mother paid a visit unexpectedly and found out. Can anyone help me locate that story so I can read it again and remember how it ended? Thanks!