The sisters Kardashian were on 'Late Show' (Weeknights, 11:35PM ET on CBS) after wrapping another successful run of their own show with Kim's engagement to Kris Humphries. But it was the x-rays, perhaps, that was David Letterman was the most intrigued by.
He also seemed either confused as to how x-rays worked, or just wanting to talk more about Kim's butt, because he asked her if the procedure hurt.
Kourtney explained that they had x-rayed Kim's butt to prove that there were no implants. As a point of comparison, Kourtney had her breasts x-rayed, because she does have implants.