Although the couple split after a nine-year marriage in October 2012, they appeared friendly as they took their sons Charles, eight, and Tennyson, six, to dinner at the Polo Lounge in Beverly Hills, along with a group of friends.
A source told Us Weekly: “They were both talking to their kids and being attentive.
"Russell and Danielle were sitting next to each other and seemed to get along well -but were never affectionate.”
The 49-year-old actor has been single since splitting from Danielle but he was linked to Natalie Imbruglia in February after they were spotted “all over one another" as they enjoyed an evening at the Beverly Hills Hotel.
An onlooker said: "They were all over one another and doing little to hide their flirting. They were being really playful and jokey with one another. You could see they really hit it off."
They then went back to Russell's suite with a group of friends where they stayed up until the early hours singing songs around his piano.
The witness added: "They then went back to Russell's room with some friends where they were partying until broad daylight.
"They were singing really loudly together around the piano, belting out some show tunes, and they looked pretty happy when everyone left them to it."
No Irish Need Apply? Not anymore