Unlike the rest of Twitter, Rob Kardashian didn’t see the first photo of Caitlyn Jenner, formerly Bruce Jenner, on the internet. The “Keeping Up With the Kardashians” reality star was first sent Jenner’s cover of Vanity Fair via text message from his sister Kim Kardashian West, and Rob didn’t even realize the photos showed his former stepfather.

“It was so funny because all the girls, we knew that Caitlyn was shooting this but my brother had no idea,” Kim, 34, explained to Access Hollywood. “So I sent it on a mass text to everyone and my brother was on it and he goes, 'Kim, why are you sending me this? Who is this woman? And why do I care?'”

Rob, 28, didn’t recognize the transgender Olympian in her female persona at all. “And I was like, 'Rob, that's Bruce! That's Caitlyn!'” Kim laughed.

Some fans might be concerned that Rob is the only one of his siblings to not comment on the cover on Twitter. However, Kim assured supporters that Rob contacted Caitlyn, 65, as soon as he realized that he knew the cover girl.

“And he was like, 'Oh my god, she's beautiful!,'” Kim said. “And then he called her and they had a love fest and it was so cute. But the moment was so funny.”

Rob was kept in the dark about the shoot, but Kim was much more involved. She revealed that she watched Caitlyn’s photo shoot and even sat next to photographer Annie Leibovitz on a flight afterwards. “I stopped by the shoot, so I saw her at the shoot, and then I sat on a flight next to Annie Leibovitz,” Kanye West’s wife told Extra. “I had to hide under my blanket, and secretly look at the photos, so that no one would see what we were talking about or doing.”

Though Rob has stayed out of the spotlight recently, he has made his support of Caitlyn clear. The Kardashian brother tweeted after her interview special with Diane Sawyer aired and noted that Caitlyn was still a role model for him.