From left: Leighton Meester, Selena Gomez and Katie Cassidy
The side entrance pops open with a bang and Selena Gomez
, Leighton Meester
and Katie Cassidy – intent upon escaping their tour group tour – come bursting out, rushing down steps. The director, Tom Bezucha, shouts "Cut!," and the girls dissolve into giggles before, arms around each other, resuming their places for another take.
It was the scene at the Eiffel Tower early Monday morning as the shooting of Monte Carlo
, a romantic comedy costarring Glee
's Corey Monteith, set for release next year.
After seven weeks filming together inside Budapest studios, one on set source tells PEOPLE, they couldn't wait to get outside – even in near freezing temperatures. 'They really get along really well. You can see they've gotten to be friends on this ... It's like a trip that way. There's this chemistry and sometimes it's almost conspiratorial, but these girls really adore each other."
With Paris enduring unseasonably cold temperatures, Cassidy (who comes rushing barefoot down the steps in a light floral minidress, holding her platform heels) was immediately helped into a parka by Gomez while Meester stood by with her Uggs.
The film's plotline revolves around "one of those inexpensive travel packages to France that sound too good to believe – and turns out to be," another source on the set explains. Gomez, Gossip Girl
's Meester and Taken
's Cassidy "find themselves on one of those 'No Time To Lose' tours, with a terrible hotel and terrible food, and through a case of mistaken identity, wind up in Monte Carlo at a ball."
Monteith joins the cast next Monday for two weeks filming in Monaco.
Gomez, Meester and Cassidy arrived in Paris on Saturday and immediately went to work: At the airport. Cameras were already in place at Charles De Gaulle airport's Terminal 2E, as the trio arrived. Mirroring the experience of millions of tourists, cameras caught their arrival, Gomez in cowboy boots and jeans, struggling to reconnect with Cassidy at the baggage carousel, both meeting Meester on a skywalk and then boarding their fake Espirits de Corps Tours tour bus.
Taking them in her charge at the airport was popular French comedienne Valerie Lemercier, who plays their tour hostess.
Paris filming continues until Friday at the Eiffel Tower, Louvre and Notre Dame locations.