Justin Timberlake and Cameron Diaz are reunited on the set of their new film Bad Teacher

They split up three years ago, but have remained on good terms, so it's no surprise to see Cameron Diaz and Justin Timberlake working together.

The stars dated for four years, but split in 2007 - they have been reunited for the new black comedy entitled Bad Teacher.

As the title suggests the story follows a foul-mouthed, junior high teacher, played by Cameron Diaz, who, after being dumped by her sugar daddy, begins to woo a colleague.

Back together: Justin Timberlake and Cameron Diaz will be reunited on the set of their new movie Bad Teacher - they were pictured filming scenes in Los Angeles

In a twist of fate, that colleague is played by Miss Diaz's ex-boyfriend Timberlake.

The two were pictured on the set of the new film, although they were not in close quarters.

Timberlake, 29, appeared pensive as he took a stroll on his own wearing a long-sleeve white T-shirt, black jeans and trainers - while Diaz, 37, spent some time with co-star Jason Segel.

Good times: The actress shares a laugh with Jason Segel on set

Co-stars: Comedy actor Jason Segel and Cameron Diaz

According to a report in U.S. magazine Life & Style the couple will film an intimate scene together.

The publication claims to have got hold of the movie's script, which features a scene where the pair start kissing and "dry humping".

But it apparently all comes to a premature end when Timberlake's character gets "too excited".

Intimate: Justin Timberlake's character is set to be seduced by Cameron Diaz's foul-mouthed teacher

'That was a mistake,' Cameron's character tells him. 'That was fast.'

After Timberlake joined the cast, Diaz told Access Hollywood: 'We're thrilled to have him. He's the best person for the job. He's going to be hilarious.

'He's clearly a very talented comedian, look at his 'Saturday Night Live' (skits). He's fantastic, he's going to be so great.'

Unsurprisingly, Timberlake's current girlfriend Jessica Biel is alleged to be unhappy about the new project.

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