Fans have been wondering for months if Kylie and boyfriend Travis Scott were engaged, but the rumors doubled down after Scott posted a photo of her with a diamond ring on her left ring finger after he performed at the Super Bowl halftime show.
While appearing on The Tonight Show Starring Jimmy Fallon, Kardashian told the eponymous host that she wasn't sure if Scott had popped the question.
"I think she would have told me," Kardashian told Fallon when he showed her the photo in question. "She's pretty secretive, but I'm sure she would have told me. I'm not really sure. But I don't think so."
In regards to the engagement rumors, Kendall said, "Not that I know of. Not that I'm aware of, so if he did, she hasn't told the family yet. But I don't think that has happened."
"Your mother would know?" DeGeneres asked of a potential engagement.
"Most likely," Kendall agreed.
As for the pregnancy rumors, Kendall shut those down.
"She's not. I think she was just like, 'We are lookin' good and we're really into each other and maybe baby number two is gonna happen.' They're practicing, right? Is that what you call it?" she teased of the couple, who welcomed their daughter, Stormi, last February. "[Stormi is] really interesting. I love her. I love her so much. She has a mind of her own. She's really clever. I don't think [Kylie is] pregnant, no."
Fans previously wondered if Kylie and Scott were engaged back in December, when Kardashian again addressed rumors that surfaced after the couple had referred to each other as "hubby" and "wifey" several times.
"I literally need to ask her," Kardashian told Entertainment Tonight at the time. "That is going to be my next question on our group chat. We were chatting on the way over here and I think we all think that's, like, you know, what they call each other. But I have no idea."
Engagement speculation has been swirling since Scott told Rolling Stone last year that "We'll get married soon. I just gotta sturdy up — I gotta propose in a fire way."