In the story of The Princess and the Frog, a lonely princess promises a kiss to frog in return for his help in retrieving her ball that had sunk into his pond. She doesn’t want to kiss him, but in the end she does, and he turns into a prince.
A fractured version of this tale could be that the frog kisses the princess and she turns into a frog.
Here are some fairy tales that you could use for your story. You are going to twist it around! You can choose another story if you have one in mind. These stories have many versions of them already. Make your own!