What happened to Kylie Jenner's butt?

Kylie Jenner posted this photo at a clothing store but what many are asking is...what happened to her curvaceous butt? She has admitted that she gets shots on her lips to make them fuller but has always denied getting work on done on her butt. 

According to unconfirmed source, her butt implant was compromised by Tyga, we are not sure if that was the case though. Another photo after the cut...