Kourtney Gets Into Ugly Catfight With "Hung Over" Khloe

Clashing With the Kardashians!

On Sunday's Kourtney and Khloe Take Miami premiere on E!, the sibs get into a nasty catfight because Khloe is hungover at a photo shoot.

"You f*cking hung over b*tch, can't you act professional and get this done for five minutes?!" Kourtney, 31, snaps in the video, above.

"Oh, I forgot, you're such a mom -- you're so perfect now!" Khloe, 25, fires back. "You've never been drunk. You used to be the party queen of life, so shut the f*ck up, you hypocrite."

When the director asks if everything's OK, Khloe complains: "She's just being rude. I have a smile on my face and I'm f*cking naked right now and fat as f*uck, are you really for real?"

"You're not fat as f*ck," Kourtney tells her.

"Shut the f*ck up!" Khloe replies.