You've done lots of intense drama. Did you need to lighten things up a bit?
"Yes, but there was no plan. I have no career plan and I had a lot of doubts before doing this, because it was difficult to judge what the movie would be like from the script. I was a little afraid about doing a comedy like that because it was a little bit like the popular stuff, you know? I mean, I didn't want to do a format, formula comedy. I love comedy but I'm afraid of popular movies because sometimes we are losing the personality or identity or some taste, you know? In France sometimes when you read comedy you don't know what kind of movie it could be."
Your character is also cynical about love, so he risks being tough to like...
"Yes, for this reason too. I was afraid to play just a seducer or a womaniser, you know? I wanted to play him more like an actor. This guy has a mission and he has to prepare like an actor to do his job well. He's more an actor than a seducer, you know? I wanted to show some doubts, that he does not always have so much confidence in him."
The chemistry between you and Vanessa Paradis is crucial. Was it instant?
"Yeah, exactly. That was another reason for doing this movie because with Vanessa we also agreed with our ideas about the movie. We wanted to add more romantic things to the script and we wanted to be careful about the comedy; not to just make it only a comedy. We wanted to show that they had some expectations [of each other] so I think that people are touched by this couple at the end. The director was very open-minded. He listened to us and reacted very quickly. It was like the same work I do in other films when it's maybe more deep drama and I was happy to do this with something more light-hearted."
You had to re-enact choreography from Dirty Dancing. That must have been hard work...
"Yes, but it was so funny. Vanessa and I love to dance so, yes, it was hard work but it was playful too and very pleasurable to do it. It was a long process, but we did it little by little. We watched the film, of course. Then we rehearsed on the set and it was a good atmosphere so we didn't feel the pressure."
Are you a fan of Dirty Dancing?
"I'm not a big fan of that film, but I am a big fan of that period, the eighties. I love a lot of American movies of that period. I love the style, you know?"
The English boyfriend played by Andrew Lincoln is very stiff. Is that how the French see the English?
"No, not at all. Not at all! Andrew Lincoln, I love this guy! Sorry, he had a bad role, but I loved the way he played the character. And when I was listening to him and Vanessa talking in English, I loved it, because I love this accent!"
You had to shoot in the Moroccan desert. How did you find that?
"It was great. Actually it was the beginning of the shooting so everyone was looking at each other, to understand each other and trying to concentrate; the way it is at the beginning of the shoot. It was very quick, but very intense as well because we had to shoot a lot of things in, like, five days. It was very quick, very fast, but it was a very good beginning, you know?"
Is the desert a good place to bond?
"Yeah, of course. It was delicious. Delicious!"
The film is already pegged for a Hollywood remake. Would you like to be a part of that?
"If they ask me, yes. But I'm not sure. I think they might ask Will Smith."
Heartbreaker opens in UK cinemas on Friday.