Kris Jenner reportedly cried tears of joy as she discovered her daughter Kylie Jenner is expecting again.

Billionaire Kylie, 24, is rumoured to be pregnant with her second child with boyfriend Travis Scott.

Kylie and 30 year old rapper Travis are already parents to their adorable daughter Stormi Webster, three.

Rumours of Kylie's pregnancy broke on Friday 20 August, but momager Kris and the rest of the Kardashian-Jenner clan are said to already be in the know and very excited about her expanding family unit.

A source told The Sun Online: "They truly are a family of 'the more the merrier' so the more they can add, they welcome that.

"Kylie's always wanted to add more kids, that's no secret so this is a really happy blessing."

 2016 Vivien Killilea/Getty Kris Jenner reportedly burst into tears of joy as she discovered her daughter Kylie Jenner's pregnancy news

It's also understood Kylie's attitude towards her pregnancy has changed this time around. Kylie hid her pregnancy with Stormi from the world, only revealing the news once she had given birth.

The insider added: "She’s already so much more confident and less worried than the first time around.

"Kris had the strongest reaction, she bursted into tears at the news of having another grandbaby.

"But all of her siblings are so happy for her too," the source added of Kylie's siblings Rob, Kim, Kourtney, Khloe and Kendall.

Meanwhile, Kylie's dad Caitlyn Jenner revealed she has another grandchild on the way, but did not let on who the parents were.

© splash / SplashNews.com Travis and Kylie are already proud parents to daughter Stormi

Caitlyn has daughters Kendall and Kylie as well as Brody, Cassandra, Burt and Brandon. 

She made the comment while visiting the Toy Store in Quincy, California, on the campaign trail, which was live-streamed on the small business's Facebook page.

Caitlyn said: "Eighteen grandchildren. I keep telling the girls — they're not too excited about this, but — I wanna go for 30.

"Thirty grandchildren. It's a round number. I just found out the other day that I have another one in the oven. Yes, I found that out the other day. So that's 19, so we only got 10 to go."

Caitlyn is currently running for governor in the state of California.

Kylie has been open about her dream to have more children. She said in an Instagram Live last year that she had hopes for a large family.

She revealed: "I want seven kids down the line, but not right now."