Twilight accidentally spent a whole day as a pair of her marefriend's panties last week, and now she can't get that out of her mind. She's devised a plan to sneak in a custom pair to cover her tracks, figuring that Rarity wouldn't notice they were missing, but when she realizes it too early, Twilight has to go through drastic measures to keep her secret. Or she could just tell the truth. But where's the story in that?

Warning: Contains clothing transformation and shenanigans that result from it...with sexy results~

Thanks to DbzOrDie for throwing things at me until I got up off of my rump and wrote this, and Numeyu for prereading!