Rob Kardashian ''Who is Caitlyn Jenner, why do I care?''

first reaction to Caitlyn Jenner's cover was epic!

The 28-year-old star apparently couldn't recognize his step-father on the cover of Vanity Fair Magazine when it was sent to him by his sister, Kim Kardashian on Monday, June 1.

Kim, who is currently pregnant with her second child, tells Access Hollywood Live at the CDFA Fashion Awards in New York City on Monday, that when she sent Rob there cover via phone, Rob said,

''Kim, why are you sending me this? Who is this woman and why do I even care?''

Kim admitted during the interview that all her sisters were eagerly anticipating the big reveal but Rob had no idea. ''It was so funny because all the girls - we knew Caitlyn was shooting this, but my brother had no idea.''

''And I was like, Rob, that's Bruce - that's Caitlyn. And he was like, "Oh my god, she's beautiful." Kim added and said Rob dialed Caitlyn and the pair ''had a love fest'' over the phone.

Rob has been keeping a low profile and being away from reality TV cameras has left him in the dark about his stepfather Bruce Jenner's debut as a female on the cover of Vanity Fair.