Julia Roberts and George Clooney reveal why they never dated despite being friends for 20 years

Julia Roberts and George Clooney have finally explained why their long-time friendship has never turned romantic.

The Hollywood stars, who have been close pals for decades, took part in a joint interview for their latest film, Ticket to Paradise, where they spoke about their sweet – but strictly platonic – relationship.

When asked if they ever enacted a "no dating policy" during a chat with Access Hollywood, Roberts, 51, offered a fascinating insight.

Watch the video above.

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"Did you ever have a no-dating policy back in the day... Years and years ago before you were ever in a relationship?" host Kit Hoover asked.

"To not date each other? I don't think we needed to state it!" the Pretty Woman actress replied. "It just seemed like the right thing to do."

Clooney, 61, agreed and said the idea of taking their friendship to the next level was never really explored.

"Julia was always in a relationship, or I was in a relationship," he explained. "We were fast friends right away.

"It's been nothing but fun for us, so I don't think that was ever really a thing."

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"[It was never like], 'Hey, let's take this to a different level'."

Roberts is married to husband Danny Moder, the father of her three children, while Clooney shares two children with his wife Amal.

Elsewhere in the interview, the co-stars were asked what their first impressions of one another were.

Clooney said Roberts "made me laugh" while the Eat, Pray, Love star simply described the actor as "gentle".

Clooney and Roberts' friendship first began over 20 years ago when they starred as exes in the 2001 movie Ocean's Eleven.

The friends have also crossed paths on-screen in Confessions of a Dangerous Mind in 2002, Ocean's Twelve in 2004 and in the 2016 film Money Monster.

Their latest project sees the co-stars portray a divorced couple.