"Our dogs were being skunked every other night for about two months straight, so this was a very normal occurrence, to be kneeling in front of the bathtub washing our dogs," the actress, 31, told PEOPLE Wednesday at the opening of Kimberly Snyder's juice bar Glow Bio in West Hollywood.
"But he was like, 'Oh, by the way, I was named PEOPLE's Sexiest Man Alive...' "
Dewan-Tatum was stunned – and amused – at the timing of his revelation. "Is that not the strangest way to tell me this news?" she said, laughing.
"I'm not quite sure why the skunk smell made him think about it," she said. "Maybe it was the fact that it was the last thing something the Sexiest Man Alive would be doing. But I don't know. Maybe it was the sexy skunk musk that made him think of it."
Once she got over the shock, Dewan-Tatum felt another strong emotion about her husband of three years: pride.
"I think it's an honor, because it's a great league of people that have been given this honor before him," she said, beaming.
"That's special," she said, "because it says he's achieved so much in his career and in his life that makes this award a possibility. But he's always been the Sexiest Man Alive to me."