The cut scene sees Maude Apatow's character Sadie sharing her thoughts with boyfriend Joseph (Ryan Lee) on what makes each member of the Kardashian family unique.
Sadie says of Kourtney Kardashian's troubled relationship with boyfriend Scott Disick: "Scott thing is hard. Because she loves him, but he's clearly out of control!"
She also offered an analysis of Kim Kardashian's distinct voice, before doing an impression of the pregnant reality star.
"[Kim's] got that high voice, that kind of sounds like Khloe's voice and Kourtney's voice combined," Sadie teased.
This is 40 is directed by Maude's father Judd Apatow and also stars her sister Iris Apatow and mother Leslie Mann.
Judd recently revealed that he cast his daughters and wife in the romantic comedy not just because of their acting talent, but also because he knew he could depend on them.
The filmmaker has also revealed that This is 40 is partly based on his life, in addition to drawing influence from the movie's star Paul Rudd.
This is 40 is now playing in the US and opens in the UK on February 14. Watch a trailer below: