Amal Clooney made George Clooney wait ''about 28 minutes'' before agreeing to marry him.

The 54-year-old actor says he ''knew fairly quickly'' that he wanted to spend the rest of his life with the British human rights lawyer, but left her speechless when he got down on bended knee to propose in April 2014 because it was ''completely unexpected.''

The 'Tomorrowland' star, who married the brunette beauty last September in Italy, explained: ''When I asked her, you know, we'd never talked about it....there wasn't like a, 'Maybe we should get married' [conversation]. I dropped it on her!

''I asked her, and she just kept saying, 'Oh my, God,' and 'Wow,' and we just sat there. And finally, I just said, 'Listen, I'm 53 at the time, or 52 at the time, I think. I said, 'I've been on my knee for about 28 minutes so I gotta get an answer out of this because I'm gonna throw a hip out. I might not be able to stand back up!''

The Oscar winner, who ''cued up a playlist'' of some of his aunt Rosemary Clooney's songs for the intimate moment at his home, and his wife have vowed to never spend more than a week apart.

Asked how being married has changed him, the 'Monuments Men' star told Charlie Rose on CBS show 'This Morning': ''[I have] someone who I can talk to about anything, and someone who I care more about than I've cared about anything. It's nice.''