Credit: AMC.

"Zou Bisou Bisou" didn't happen on a whim. During a conference call with reporters today, "Mad Men" actress Jessica Pare said that for Sunday's season five premiere, in which Megan serenades Don at his 40th birthday party, she lip-synced along with a track she previously recorded.

"I worked with David Carbonara, who does the music for the show, and I got to go into a real, grown up recording studio," she said. "We're hearing what I did in the recording studio."

Prior to that, Pare said she listened to the French pop song "a whole lot" and Matthew Weiner, "Mad Men's" executive producer, "gave me some pretty comprehensive notes to go along with it." She estimated that including dance lessons with a choreographer, "it came to a week and a half of rehearsing. But I was doing it for the entire 'Mad Men' cast, I had to know my stuff."

As for the viral popularity of the performance and the fact that the song is now available for download on iTunes, Pare said she's "thrilled."

"I never thought I would make a single," she said, "let alone an actual, physical record, because there's a 7-inch vinyl out there too."

Pare also talked about Megan and Don's raunchy romp on the carpet - "Is there really any problem that can't be solved that way?" - and why she thinks Megan and Don may have more longevity than some of his other flings.

"She is his equal," she said. "Megan is Don's equal in a lot of ways. One of the ways that she has some kind of power over him is that they are such a great match sexually and physically."

As for rolling around with Jon Hamm in real life?

"He's not that bad looking I guess," she laughed, "and he's really easy to work with. There is nothing bad about working with him."