The phrase "Well butter my butt and call me a biscuit" is an expressive saying used to convey surprise or astonishment. It captures a lighthearted and humorous tone, suggesting that the speaker was not expecting a particular outcome or revelation. This kind of playful language often adds charm and personality to writing, making it more engaging for readers.

In the context of the book "Flat-Out Sexy" by Erin McCarthy, this quote likely reflects the fun and quirky style of the narrative. The phrase can serve to highlight a moment of unexpected humor or a character's reaction to an unbelievable situation, contributing to the overall tone of the story.