By Christine Rendon For Dailymail. She has previously had to deny she's had any form of breast enhancement surgery, putting her larger chest size down to hormones and getting older. But fans were speculating about Kylie Jenner's considerably assets on Friday after the year-old posted a very busty looking Instagram. Sporting a plunging black vest top, there was no disguising the businesswoman and reality star's considerable cleavage. Speculation: Fans were abuzz on social media about the size of Kylie's cleavage after the star posted this Instagram on Thursday. Another follower added: 'She was hotter before the boob job,' whole many others speculated that her blonde busty look made her look like Rob Kardashian's girlfriend Blac Chyna.