Rob Kardashian admits his first crush was on sister Kim

Rob Kardashian's fiancee Blac Chyna let slip the reality star's first crush was on his sister, Kim Kardashian.

The 29-year-old star made the embarrassing confession during a promo clip for Rob and Chyna, his reality show with pregnant fiancee Blac Chyna.

The couple was discussing their former favorite pin-ups, when Rob declared Ricky Martin was in fact Chyna's childhood crush, leading her to burst into an impromptu rendition of the singer's hit Livin' la Vida Loca.

However, things turned a little weird when she revealed Rob's first crushes were Jennifer Lopez, and his older sister Kim. The sock designer blushed and bashfully replied, "That is also pretty accurate...". "These are facts," Chyna then stated.

Fans on social media were baffled by the revelation, with one querying on Twitter, "I'm sorry it's been a long day. Did he just say he crushed on his SISTER?! Or did my exhaustion mishear things?"

Break-up rumors recently surrounded the couple, following reports Rob and Blac were in fact living separately until their baby girl is born in November (16).

However, Rob was quick to pour scorn on those rumors with a Snapchat video on Wednesday (28Sep16), showing him in bed with Chyna. The reality star was trying to capture his baby girl kicking, but later gave up, noting she wasn't about to move for the camera.

The Snapchat video was also the first public display of unity between Rob and his 28-year-old pregnant fiancee since he shared his sister Kylie's number on Twitter.

Rob's sisters Kim, Khloe and Kourtney Kardashian, along with half-sisters Kendall and Kylie Jenner, reportedly threw a baby shower for their brother at the weekend (24Sep16), which enraged the impending father-to-be.

The Kardashian clan wanted to throw the pair separate bashes after learning Rob and Chyna were not getting along, however he was upset at their plans and vented his anger on Twitter.

"Didn't invite the Mother of my child to a baby shower you all were trying to throw for me!!? You all must have lost your damn minds," he posted on the social media site, before sharing Kylie's private phone number with his 6.5 million followers.