AceShowbiz - Katie Holmes and Chace Crawford have teamed up for an odd new romantic comedy - she plays the "Gossip Girl" hunk's former babysitter-turned-lover in "Responsible Adults". Both stars grew up on big TV hits - Holmes starred in cult series "Dawson's Creek" - and now they're teaming up on the big screen in a film that is currently being shopped around at the Cannes Film Festival.

The synopsis, obtained by Deadline, reads, "Holmes plays 30-year-old-med student Liz Quinn, who meets charming 22-year-old Baxter Wood (Crawford). Their chemistry is electric until she realizes they have already met - she was his babysitter 15 years ago. But Baxter isn't going to give up that easily on the one person he always felt knew him better than anyone else."

Katie Holmes recently wrapped up the filming of "The Son of No One" which also stars Channing Tatum. Chace Crawford, meanwhile, will be seen in "Peace, Love, and Misunderstanding".