Kim Kardashian's nephew is so obsessed with her kitten she thinks they will need to "share custody".

The reality TV star was given the new pet by her boyfriend Kanye West. The white feline is called Mercy and Kim's sister Kourtney's son Mason is particularly taken with her.

The two siblings are currently living together in Miami while they shoot a TV show and Mason has formed a strong bond with Mercy.

"He just cannot live without her! I'm going to have a really big problem if he gets too attached," Kim told Us Weekly.

"I get to wake up with Mason every day - he actually wakes me up every day looking for my kitty. We can maybe share custody, so when I'm on the road there'll be a permanent babysitter."

Kourtney and her boyfriend Scott Disick recently welcomed their daughter Penelope into the world. Mason, two, is enjoying being an older brother to the two-month-old.

Kim has been amazed by how well Kourtney has coped with having two little children.

"It's a lot to juggle when she works as much as she does," Kim explained. "It's hard with two kids. She does it so effortlessly. I have a lot of friends who have two kids and she definitely makes it seem the easiest."