Rob Kardashian once had a crush on his sister Kim Kardashian West.

Rob Kardashian and Blac Chyna

Rob Kardashian and Blac Chyna

The 29-year-old reality TV star, who is expecting his first child with fiancée Blac Chyna, dropped the bombshell during an interview with E!

The couple were asked to reveal their first crushes, to which Rob replied: "Her childhood crush is Ricky Martin"

But Chyna wasn't embarrassed by his revelation, in fact she started giggling and singing his 1999 hit 'Livin' La Vida Loca'.

But it wasn't long before she sought to get her own back on her other half.

She exposed Rob's crushes, saying: "Jennifer Lopez."

Prompting Rob to reply: "Yeah, pretty accurate."

She then added: "Kim Kardashian..."

To which Rob blushed and admitted: "That is also pretty accurate".

Chyna added: "These are all facts!"

Rob is son of the 'Keeping Up with the Kardashians' momager Kris Jenner, brother to Kim, Khloe, Kourtney, and his half-sisters are Kendall and Kylie Jenner.

Chyna and Rob, who had been at the centre of rumoured split earlier this week, put on a united front on Wednesday night (28.09.16) when Rob shared a Snapchat video of Chyna's baby bump, trying to capture their baby girl kicking but wrote in the caption "ain't moving for the camera".

They are also said to be "living separately" until their baby is born, sometime in November, after they started "fighting more", but since they have been in separate houses they are getting on better.