George Clooney and his wife Amal write love letters to each other.

The 'Ticket to Paradise' actor recalled how his agent knew he was "going to marry" the barrister as soon as he met the 44-year-old beauty in 2013, and though the 61-year-old star was initially skeptical, the pair quickly hit it off.

He said on 'The Drew Barrymore Show': "Well its funny she came to the house in Como with a friend of hers to visit and immediately I was like…'

"The funniest thing is Bryan Lourd my agent called me, he had just met Amal at some other thing and she was like, 'Yeah I am going to go to Como with a friend of mine,' and he called me up and he said, 'There's a girl coming to your house that you are going to marry.'

"I was like, 'You're an idiot. You know that's not going to happen.'

"And then in comes Amal and we stayed up all night talking and I started writing her a bunch of letters."

Drew asked: "Like on pen and paper."

And George revealed he and his wife - who he wed in 2014 and went on to have twins Alexander and Ella, now five, with - have kept up the letter writing tradition.

He said: "Yep, we still write letters. Leave them on the pillow."

Meanwhile, the 'Money Monster' actor hailed his work on 'E.R.' - on which he played Dr. Doug Ross from 1994 to 1999 - as the "job of a lifetime" because he made so many close friends, who he is still in contact with today.

He said: "I guess it was the friendship I have with all of them and that I continue to have.

"I had [Anthony] Edwards at the house in Italy three weeks ago — he and Mare came."

Noting he is also "really close" to Julianna Margulies and Noah Wyle, he added: "They're really good friends. And so I feel that [show] was a job of a lifetime. And it changed my career."