The Mulholland Drive actress and the Ray Donovan star, who have two children together, announced they were splitting in September (16) after 11 years together. And Naomi proved there is no bad blood between them when she celebrated the opening night of the play Les Liaisons Dangereuses, in which Liev plays serial seducer Le Vicomte de Valmont, on Sunday (30Oct16).

She hit the red carpet at New York's Booth Theater wearing a black coat and full-length dark silk shirt as she smiled for the photographers and posed with Lisa Rubin, the writer of her upcoming Netflix show Gypsy. Other guests included Pierce Brosnan, Alan Cumming and Megan Hilty.

In September (16), the former couple issued a statement which read, "Over the past few months we've come to the conclusion that the best way forward for us as a family is to separate as a couple.

"It is with great love, respect and friendship in our hearts that we look forward to raising our children together and exploring this new phase of our relationship."

They first proved their split was amicable when Liev posted a sweet message to Naomi on Instagram when she turned 48 two days after their statement. Naomi had shared a picture of herself as a blonde-haired baby and he commented, "Happy Birthday Sweetheart."

To celebrate his 49th birthday weeks later, she returned the favour and shared a snap of Liev smiling as he carried their two sons, nine-year-old Alexander and seven-year-old Samuel. She wrote in the caption, "Happy Birthday to this one!!"

The play marks Liev's first role on Broadway in six years and he recently revealed he had completely forgotten his lines during a preview and had to call out for the prompter's help.

"I have never called 'line' in my professional career once," he explained on U.S. breakfast show Today. "On our first preview, I broke that cherry and I called 'line' about halfway through the show and I just remember, I must have taken a seven-to-10-second pause, which onstage is an eternity!"