Arnold Schwarzenegger was joined by her estranged wife Maria Shriver for his 64th birthday on Saturday.

The former Governor of California dined at Barney's with Maria and two of their four children, 17-year-old Patrick and Christopher, 13, and despite their recent divorce announcement – which came shortly before it was revealed Arnold had fathered a son with his housekeeper – the pair appeared to be on good terms, with Maria even paying for the lunch.

A source told "Maria grabbed for it. She was already pulling out her wallet and gave her credit card to the waiter. While she gave him the card, she also ordered Arnold an espresso."

When they left, Arnold was overheard referring to Maria as "darling", but she left alone.

The couple were recently said to be locked in battle about spousal support, with the 'Terminator' actor's lawyer Bob Kaufman asking the judge to make sure each party paid their own legal fees and strike any right to support on Maria's part.

The couple have no prenuptial agreement, meaning all assets and property accrued during their 25 year marriage – estimated at around $400 million – will be divided equally.