It it possible to increase the length of my butt crack? (Photo)

Hello and Great Question. I appreciate the time you are spending researching this procedure. My name is Dr. Matthew J. Nykiel. I am a Board Certified Plastic Surgeon, a Fellowship Trained Cosmetic Surgeon, and a Butt Augmentation Specialist.
Based off your photos you would be a great candidate for a BBL which would consist of lipo 360 and a fat transfer to your hips/butt giving you more of an hourglass figure. I would definitely recommend doing an in person consultation with a board certified plastic surgeon who specializes in this procedure and who can suggest what is needed. 
I hope that helps! Best of 
Luck! 
Matthew J. Nykiel MD

There are no established surgical procedures specifically designed to lengthen the buttock crease or "butt crack." The length of the intergluteal cleft is largely determined by anatomy, including the natural distribution of fat and skin tension in the area.
However, some individuals seek cosmetic procedures to improve the appearance of the buttocks as a whole, which can enhance the overall shape and contour. Procedures like Brazilian butt lift (BBL) or fat grafting can alter the size and shape of the buttocks, potentially changing how the butt crack appears in relation to the rest of the area, but they don't directly modify its length.
It’s important to consult with a plastic surgeon who specializes in body contouring to discuss your concerns. They may offer personalized recommendations, but it’s unlikely that any procedure will specifically increase the length of the butt crack itself.

You should be a good candidate for lipo and BBL.  Fat can be taken from many different areas (abdomen, sides, back, bra rolls, thighs, arms, etc) depending upon the areas of excess and what your goals may be. Most patients get an immense benefit with maximal liposuction of the abdomen, sides, and back to obtain the smallest waist possible and then maximal fat transfer to the buttocks and hips. The goal is to transfer fat from areas where you find it displeasing to areas in which you would like more volume.