Carol Burnett And Friends - The Complete Series on DVD - www.carolburnettdvd.com

Carol Burnett is one of the most beloved comediennes in the history of American television. Tuesday night, she found herself in the middle of a public spat with Joan Rivers on "Joan & Melissa: Joan Knows Best?" (Tues., 9 p.m. EST on WE) in a moment that had the feel of a scripted scene.

Looking for a celebrity guest to make an appearance at a charity event at her daughter Melissa's son's school, Joan cornered the actress at a restaurant and went over to her table for a quick chat. From the get-go, it was clear that Burnett wasn't too excited to see Rivers. When Rivers hugged her hello, Burnett rolled her eyes and braced for an uncomfortable conversation.

Burnett rebuffed Rivers' attempts to get her to appear at the charity auction, saying that she was busy on the date it was scheduled. She also commented on how Rivers had "done something" to her face, prompting Rivers to beam about all the work she's had done.

The uncomfortable conversation reached a boiling point when Rivers told Burnett she was detecting some animosity from her. At that, Burnett got up from the table and explained why she was holding a grudge. "Hawaii!" she said, and stormed out of the restaurant.

What exactly happened in Hawaii? Earlier in the episode, Melissa revealed that Joan pushed Carol into the ocean on a family vacation there 30 years ago, and she was stung by a jellyfish. Joan never apologized.