Jennifer Aniston and Lisa Kudrow starred in Jimmy Kimmel's swearing game "Celebrity Curse Off" last night, and it was hilarious.

The former Friends co-stars participated in the contest to see who has the foulest mouth on late night show Jimmy Kimmel Live, uttering as many curse words as they could muster. And we were delighted to see they are both pretty impressive when it came to inventive curses!

"Here at the show we’re known for bleeping and blurring things unnecessarily - but for once, the bleeping is necessary. If you are faint of heart cover your ears because it's time once again for America's most foul-mouthed competition," said Kimmel as he called up Aniston, 45, and Kudrow, 51.

The rules of the quick fire-style competition are that each star is given five seconds to come up with a curse and each word can only be used once.

Jennifer Aniston and Lisa Kudrow reunited on screen to compete in swear-off competition