I have a bony butt? When I sit and bend over my sit bones stick out. It's very embarrassing and sometimes painful (Photo)

Besides the buttock issue, seeing other details needed for evaluation is impossible in these photos. Liposuction of the abdomen, flanks, and lower back is usually a source of fat grafts; only based on in-person evaluation could one give you a more accurate answer. In-person or teleconference consultation with a board-certified plastic surgeon with expertise in BBL is recommended. Good luck.

Based on the information provided you are normal without need for surgical intervention.
The bones you are referring to are most likely your Ischial tuberosity.
Best,
Mats Hagstrom MD