EXCLUSIVE PHOTOS - Olivier Martinez Has Romantic Dinner With French Actress Elsa Zylberstein

Whoa! Halle's not gonna be happy when she sees this!

Olivier Martinez had dinner and drinks with French actress Elsa Zylberstein Friday at Chateau Marmont while girlfriend Halle Berry was out at the park playing with Nahla.

Our photographer tells us:

"At first, the dinner seemed like two friends just meeting up. But then, after a pretty long time together in the garden cafe and once it started to get dark, they seemed to be more romantic. By the time they said goodbye, they really seemed to be more than friends. She was obviously into Olivier and he started to be kind of flirty with her."

Yikes! Looks like quite a passionate goodbye for two friends!