In an attempt to further refine one of my other models, in the search for an even more aesthetically pleasing and anatomically uncommon female backside, the fit midriff and bubble butt combination, which is basically getting two aces on the deal in a game of Hold 'Em, I may have found it.

This Lora should give your subject a very toned midriff, and dependent on perspective and pose, an ass that indicates she also doesn't skip working out the glutes.

Example prompt:

A high quality glamour photo of a woman.  

She is looking at the viewer with a seductive smile.  Professional fashion photoshoot lighting.

The photo is a close-up.

The photo was taken from her side.

She has glossy brown hair in a high ponytail.  She has striking grey eyes.

She is wearing a black thong bikini.  Her wide hips emphasize her narrow waist.  She has small perky breasts. 

She has an athletic body with a narrow waist.  She is posing, her back arched.  She has smooth flawless skin.  She is an attractive adult woman in her 20s.

She is reclining.

She is outdoors at a luxurious jungle resort, white stucco columns and dark green banana leaves recede into the blurry background