13 weeks post op BBL. Butt still hard. Will everything soften out?

At just 3 months out from surgery there is still likely some swelling present.  I think you will find things softening over the next 3 months.

Bruising typically resolves in 1 to 2 weeks.  The hardness will take weeks or months to improve.  A lot of this will depend upon the amount injected and the technical aspects of surgery. Kenneth Hughes MD, ABPS Board Certified Plastic SurgeonLos Angeles, CA

Hello dear!!
Thanks for the question and provided information as well.
You are still early on the healing process, it can take up to six months to see your final results, so please be patient. At the stage you are in, inflammation is normal.
If you have any concerns, please follow up close with your plastic surgeon.
Good luck :)

three months almost all patients have results that are final or close to final. It is rare I see patients what firmness this far out.  Your description is subjective and much depends on how the procedure was done.  At this point there is nothing you could or should do other than give it more time then follow up with your provider and share your concerns with him or her.  There are no treatments that can help soften things up or speed up the process.  Things may improve with time but you're getting up at a point or results are getting closer to final if not final already.  Best, Mats Hagstrom MD