Does a BBL with fat injected above the muscle yield cellulite and saggy results?

Hello dear!
Thanks for the pictures and provided information as well.
Based on your photos, you are a great candidate for liposuction and BBL and you'll get great results. 
Answering your question, yes, it's possible that you'll get cellulite but if you get proper massages, the possibility dicreases. 
In general, know that you need to be physically healthy and at a stable weight, have realistic expectations, be a non-smoker and your BMI needs to be 30 or less.
l recommend you to make an appointment with a board certified plastic surgeon to talk about your goals and anything you need to know.
Good luck :)Dr. Luis Mejia.

Fat transferred to the buttocks can and does improve dimpling.  In the thousands of BBLs I have performed, I have not found the buttocks to look saggy as you heal. In general, the dimpling, which is different from true cellulite, is improved with the BBL and typically resolves with time as the fat becomes part of your body and swelling subsides.

Dear samjake,
based on your photos, you look like a good candidate for a BBL. Liposuction of your abdomen, back and flanks should give you more curves and hourglass shape and fat transfer to buttocks should give you more projection. I would suggest you to consult a board-certified plastic surgeon because only after a thorough examination you will get more information and recommendations.
Daniel Barrett, MD
Certified, American Board of Plastic Surgery
Member, American Society of Plastic Surgery
Member, American Society of Aesthetic Plastic Surgery