Justin Timberlake and Cameron Diaz are back together again – and not only in their fans’ dreams.

The two ended a four year relationship in 2007, but Timberlake has snagged the male lead in Diaz’s foul-mouthed comedy “Bad Teacher”.

Diaz, 37, plays a man-thieving, cursing seventh-grade teacher who, after she’s dumped by her boyfriend, goes after the boyfriend (Timberlake) of a colleague (Lucy Punch). The movie is being directed by Jake Kasdan for Columbia.

Timberlake, 29, plays a substitute teacher who is also in line to inherit a family fortune.

The cast also includes Molly Shannon, Jason Segel and Eric Stonestreet (“Modern Family”).

John Krasinski, Joel McHale, Timothy Olyphant, Guy Pearce and Adam Scott were all in the running for the role that went to Timberlake.

Both Diaz and Timberlake voiced roles in “Shrek the Third” in 2007, and a great deal of attention was paid to their body language at that movie’s premiere after what was said to a contentious break-up.