WATCH: Kourtney and Khloe Kardashian Show Off How to ‘Know Thy Sister’

Staying Smooth
This is what Kourtney and Khloé Kardashian do to prevent wrinkles.

Kourtney Kardashian teases a new video clip from her app in which she throws down the gauntlet to older sister, Khloe Kardashian, in a challenge entitled “Know They Sister.”

In the clip, Kourtney asks Khloe to reveal her favorite band from high school, which happens to be none other than the ’90s Swedish pop group, Ace of Base.

As for Kourtney, she reveals to Khloe that she doesn’t actually have a favorite Disney movie because she very democratically loves them all.

The entire video is available via Kourtney’s app and solves the riddle of which reality TV sister knows the other one best.