Brody Jenner had no idea his half-sister Kylie Jenner was pregnant.

The former 'Hills' star only found out the 20-year-old reality star was pregnant when Kylie told the world she'd given birth on Sunday (04.02.18), after keeping it a secret for the whole nine months.

He said: ''Well, to be honest, I didn't even know she was pregnant for the entire pregnancy.

''Now I found out and would love to see her.''

The 34-year-old hunk - who shares Caitlyn Jenner as a parent with Kylie - admitted that he hand't been in touch with Kylie or the Jenner/Kardashian family in ''a couple of years'', but that he would love to meet baby Stormi Webster, whose last name is her father Travis Scott's real surname.

He told TMZ: ''Relationship's always been there, but you know they're busy.

''It is what it is. I would love to meet the baby.''

Meanwhile, Caitlyn shared a gushing tribute to Kylie and her newborn daughter on hearing the news.

The 'I Am Cait' star - who was known as Bruce Jenner before undergoing a gender transition - wrote a sweet message of support after she welcomed her little girl into the world February 1.

Alongside a picture of Kylie herself as a baby, she wrote on Instagram: ''My daughter just had a daughter. It's amazing to be by your side through this journey. She's SO beautiful already. Can't wait to watch her grow. Throwback to my baby, as a baby @kyliejenner (sic)''

Soon after the birth, Kylie's mother Kris took to social media to reveal she feels ''blessed beyond belief'' after Kylie welcomed her first child.

Sharing a link to the video Kylie dedicated to her daughter, Kris wrote on Twitter: ''God is SO good!! I am so excited and thrilled to welcome another precious baby girl to our beautiful, ever growing family. We are blessed beyond belief! (sic)''

Announcing the arrival of her daughter and explaining why she didn't share her pregnancy with the world, she wrote: ''I'm sorry for keeping you in the dark through all the assumptions. I understand you're used to me bringing you along on all my journeys. My pregnancy was one I chose not to do in front of the world.

''I knew for myself I needed to prepare for this role of a lifetime in the most positive, stress free and health way I knew how. There was no gotcha moment, no big paid reveal I had planned. I knew my baby would feel every stress and every emotion so I chose to do it this way for my little life and our happiness.''