Carol Burnett
Carol Burnett opened old wounds late Tuesday in an awkward public spat with Joan Rivers on the reality TV show, "Joan & Melissa: Joan Knows Best?" It seems Burnett holds a long-running grudge against Rivers. What happened in Hawaii? REUTERS/Max Morse

For Carol Burnett, it seems that what happens in Hawaii doesn't always stay in Hawaii. The longtime American comedian opened old wounds late Tuesday in an awkward public spat with Joan Rivers on the reality TV show, Joan & Melissa: Joan Knows Best?

Burnett, 78, revealed in an episode of the show that she has a long-running grudge with Rivers.

In the episode, Rivers approaches Burnett as she is dining with a male friend.

Oh you've done something, Burnett jokes to Rivers. The 78-year old Rivers admits she has had significant plastic surgery on her face - new chin, new nose, cheekbones - and the pair discusses briefly each other's marital statuses.

After a bit of small talk, Rivers asks Burnett if she would be willing to pose as a celebrity guest for a charity auction at her grandson's school. Burnett nods along with Rivers' offer, but seems displeased.

I really can't Joan, Burnett says, before Rivers has the chance to propose the date.

When Rivers explains the guest appearance would be for Memorial Day weekend, Burnett declines the invitation.

Oh, I'm sorry, she says. I'm busy all of May.

Surprised at Burnett's uncomfortable responses, Rivers finally asks the comedian, Well, what is it?

In a hurry, Burnett slams down her napkin.

Hawaii! she shouts, storming out of the restaurant.

The awkward encounter has left many viewers wondering if the pair of comedians holds a long-time grudge or if the scene was scripted by writers for the show. On The Red Carpet reports that Rivers may have once ruined Burnett's family trip to Hawaii. The comedian has allegedly never forgiven Rivers for ruining her trip.

Strangely enough, following the episode Tuesday night, Rivers tweeted, I LOVE Carol Burnett!!!

No matter what the real story might be, we may never know what really happened in Hawaii.

Watch the clip of Burnett and Rivers' awkward encounter here.