AceShowbiz - Actors Marion Cotillard and Adam Driver were tasked with "mimicking cunnilingus" to get the most out of their vocals during love scenes for their new movie musical "Annette".

The stars helped to open the Cannes Film Festival in France on Tuesday (06Jul21) with the premiere of their new project, which was directed by Leos Carax and features Cotillard as a top opera singer and Driver as her comedian husband.

While the French actress is no stranger to shooting big screen musicals, she revealed working with Carax was completely different as they had to put themselves in some odd sex positions to belt out their vocals live on set.

Speaking at Cannes, the "La Vie En Rose" star said, "On most classic musicals, you record your songs in advance and then you do playback on the set. But there, Leos wanted everything to be completely live."

"It added to the complexity of the set: we found ourselves singing in very complicated positions, doing back-crawling or mimicking cunnilingus; acrobatic positions that technically modify your song (the way you sing)."

"But that was the effect Leos was looking for: he wanted the voices modified, thwarted, by the real (situation)."

Cotillard was particularly intrigued by Carax's vision because the movie musical is the first she can recall in which the characters are shown having sex.

"We strangely never see people f**king or doing trivial things in musical comedies," she shared.

"Annette" is Carax's English language debut and his first film since 2012's "Holy Motors". It features music from the band Sparks.