At such a young age, Kim Kardashian has already noticed a strain on the relationship between her children, North West, 4 and Saint, 1.

Kim Kardashian West revealed in a recent appearance on live TV that her daughter North is not a huge fan of her little brother Saint and it’s evidently a problem for her.

“I don’t know if it’s because she’s the older sister. I don’t know what it is,” Kardashian said while co-hosting “Live with Kelly and Ryan” alongside Ryan Seacrest on Monday. “I thought it was a phase. She does not like her brother and it’s so hard for me.”

The reality star also explained that jealousy is an issue for North when it comes to her younger brother.

“I thought it was like, ‘OK, a couple months; she’s just warming up to it.’ She got so jealous when I would breastfeed and all that stuff. Now, the phase isn’t going away!”

Kim, who first became a mom in 2013, told Ryan Seacrest North thinks she’s “outsmarting” her whenever she tries to exclude Saint.

“She’s like, ‘We’re having a tea party. No boys allowed. Dad can’t come. No boys!’ She’ll slam the door on her brother’s face, and he’ll just start crying.”

Saint “likes to imitate her now,” the 36-year-old reality star continued. “So if she’s crying, then he’ll just start fake crying. I’m like, ‘One of you! I can’t pick up both of you and figure it all out!’”