Jennifer Aniston and Vince Vaughn may be at each other's throats on screen in the new film "The Break-Up," but their electric chemistry behind-the-scenes has turned into one of Hollywood's hottest couples.
Vaughn told "Good Morning America" he likes Aniston's "genuineness.
"What you see is what you get," Vaughn said. "Jennifer is a very warm person, very bright person, very kind and considerate."
Vaughn and Aniston are not the first couple to meet "on the job" and they won't be the last. The list of celebrity couples is long.
In one of the most infamous on-set romances, Aniston's ex, Brad Pitt, left her for Angelina Jolie after sparks flew during the filming of "Mr. and Mrs. Smith."
"The chances of Brad Pitt picking up someone in the line at Bed, Bath and Beyond are pretty slim," said comedian Hal Sparks.
Just a couple years later, "Brangelina" is now a family of five. Jolie had already adopted two children and just gave birth to a daughter, Shiloh, last week.
Before Katie Holmes, Tom Cruise roared into Nicole Kidman's life on the set of "Days of Thunder." Later cruise met Penelope Cruz while filming "Vanilla Sky."
On-set romances are nothing new, having been around since the days of old Hollywood. Richard Burton wooed Elizabeth Taylor on the set of "Cleopatra" in 1962 and began an affair while both were still married. And Spencer Tracy romanced Catherine Hepburn during "Woman of the Year" in 1942.
Months away from home, isolated locales, long hours and those steamy up-close-and-personal scenes often form a recipe for popcorn passion.
"Given the opportunity to have someone sit in front of them and say, 'I love you, I don't want you to die,' they fall in love with the characters," Sparks said.
As salacious and captivating the Hollywood romances are, they rarely come with a magical Hollywood ending. Jude Law and Sienna Miller went from the bliss of filming the movie "Alfie" to the heartbreak of "nannygate" when Law had an affair with his children's nanny.
"Good Will Hunting's" Minnie Driver was dumped by co-star Matt Damon on "Oprah."
Jennifer Lopez's and Ben Affleck's much-scrutinized engagement flopped just like their movie "Gigli."
"There are biblical relationships that would have been wrecked by 'Gigli,' " said Sparks.
Affleck did find love later with another one of his leading Jennifers -- Jennifer Garner, who he met on the set of "Daredevil."
"The key to a long-term celebrity marriage [is] one, meet on a crappy project, [and] two, don't get married," said Sparks.
So perhaps the secret to success doesn't involve a wedding ring. Goldie Hawn and Kurt Russell met on the set of "Swing Shift" 22 years ago and are still going strong.