As a joke, Celestia convinces Twilight—through no small amount of manipulation—that she needs to wear a banana costume for Celestia's amusement. What Celestia doesn't expect is just how sexy she finds it, or how quickly things get hot and heavy. Well, maybe she expected it a bit. Either way, she's going to peel this banana if it's the last thing she does.

Reading by LimeyPony here.