Cameron Diaz, Justin Timberlake Bad Teacher Field Trip filming costars glasses Cameron Diaz, Justin Timberlake Bad Teacher Field Trip filming costars glasses

I'm sure Cameron Diaz and Justin Timberlake would not have agreed to work on a movie together if they weren't at least somewhat friendly with one another, but is it possible that something more might happen between the two former lovers?

Yesterday afternoon we spotted the two on the set of Bad Teacher in Los Angeles, and they couldn't seem to stop smiling and giggling. Flirting or just friendly exes?