Oscar-winner George Clooney added new details Thursday to a story he’s told publicly about how he proposed to his wife, attorney Amal Alamuddin.

“I think [it was] about six months till I actually thought I might pop the question,” Clooney, 54, said Thursday on “The Ellen DeGeneres Show. “We talk about it. It wasn’t like, ‘Oh, maybe we should get married’ or anything.”

Instead, he said, he sprung it on her unawares.

“I plotted the whole thing out,” the “Hail, Caesar!” star told DeGeneres, saying he had a ring hidden and a recording of Cole Porter’s “Why Shouldn’t I?” by his aunt Rosemary Clooney set to play. “Everything was planned out. I’ve cooked dinner. And she comes in and she’s just come back from London... and now she’s like, ‘Well, maybe we’ll just order in.’ I go, ‘No, no, I, I, I, I made dinner,'” he recalled with a comic stammer.

After the meal, he asked Alamuddin, who turned 38 on Wednesday, to reach into a box to fetch a lighter for a blown-out candle.

“And I’ve got just the ring sitting in there. And she pulls it out and she looks at it and she’s like, ‘It’s a ring’” — in a voice Clooney rendered as her not realizing what kind of ring but rather “like somebody had left it there some other time.”

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After seeing it still wasn’t registering with her, “I got down on my knee and I said, ‘I couldn’t imagine spending the rest of my life without you,’ And she kept looking at the ring and she was looking at me and she was like ‘Oh my God.’”

After about 25 minutes with no answer, he said, “I finally, literally, said, ‘Look, I hope the answer is yes, but I need an answer because I’m 52 and I could throw out my hip pretty soon if I don’t get an answer.’ And then she said, ‘Oh. Oh, yes.’”

The divorced Clooney, who had famously sworn off remarrying before meeting Alamuddin, told DeGeneres, “It was one of those funny things. From the minute we met, we just hit it off, and from the minute we met we sort of felt like we were going to be together.”