But luckily the 28-year-old's momma, Tokyo Toni, is more willing to share!
So while she wouldn't share the sex of the baby, though she does know, Tokyo dished on the happy couple in a new interview with 93.9 WKYS on Wednesday.
"They're hot. They exude excellence in a very modest way. I'm very close with Rob. We're so close we talk for hours on the phone."
She's such a #proudmom! Kris Jenner might want to watch out. LOLz!
But according to Tokyo, her daughter didn't come to her with news of relationship with Rob. In fact, she shared that she confronted Chyna with the media reports before she finally got a chance to speak with the 29-year-old fiancé for the first time.
Additionally, the grandma is "very pleased" about Rob being the father of their bundle of joy, as well as KJ as grandma.
It even sounded like Tokyo was cool with the whole Kardashian clan after spending a whole day with them at Six Flags in Cali!
Hear her explain how it all went down by pressing PLAY on the videos (below):
[Image via Instagram.]