"You're married to two guys, right?" David joked. Watch Kim try to fake-laugh her way out of this one!
Promoting the new series of her show with sister Kourtney, Kim and Kourtney Take Miami, Kim was pressed by David about why her 72-day marriage is taking so long to end.
While Kim just wants Kris "to be happy and us to move on", Letterman pressed her about Kris' lawsuit against her demanding an annulment.
"I would love to give him an annulment, but ... the only legal way to get an annulment is if fraud were involved, so that's what's tricky," she answered.
"He is suing me for an annulment based on the fact that I frauded him into marrying him for publicity."
Kourtney came through for her sister with this zinger: "I think if she was going to do it for publicity, she'd pick someone that people knew!" Ouch!
Kim also fired up, saying that the 72-day marriage jokes "have to stop" since she's "really been married for almost two years". Well, okay then!
Kim's mum Kris Jenner is reportedly against the idea of Kim granting her ex an annulment given the "the possible ramifications it could have for the Kardashian empire", an insider told Radar Online.
"Kris is concerned about the negative press and criticism Kim will get if she goes through with it," the Radar source said.
"Kris' main concern is how E! would react to Kim's decision since the network aired their wedding special."
Pregnancy and divorce dramas aside, Kim has tried to distract everyone yet again with her cleavage.
Check out this just-released video of her raunchy photo shoot for Saudi Arabia's Hia magazine on her recent Middle East trip:
View slideshow: The world according to Kim