First Pic: Justin Timberlake, Cameron Diaz Reunite ... in Movie

Credit: Sony Pictures

Justin Timberlake is back together with ex-girlfriend Cameron Diaz -- on the big screen.

And so far, they seem to be all smiles about teaming up for Bad Teacher -- at least that's what it looks like in the first photo released from the movie set.

In the comedy, which began filming this month, Diaz, 37, plays a middle school teacher who gets dumped by her boyfriend and begins hooking up with another teacher, played by Timberlake, 29. (There's even a hotel room sex scene!)

This isn't the first time the two -- who split in 2007 after nearly four years of dating -- have been spotted together this year. They were seen mingling and laughing at the Hope for Haiti Now telethon in L.A.

How does Timberlake's current girlfriend, Jessica Biel, feel about the reunion?

She has said she is "super-excited" to see the film and that "it sounds fantastic."

Tell Us: Will you see Bad Teacher?