Here's a huge treat for Mad Men fans: Some lovely person has just leaked a thank-you video for creator Matt Weiner made by the cast and crew of Mad Men (apparently at the season-three wrap party? Everyone seems a little loaded!) singing "Bye Bye Birdie," a song that played a big role last season. See Jon Hamm make silly faces behind a (disappointingly lip-synching) January Jones! Watch John Slattery sing in a long red wig! Giggle at the sight of Elisabeth Moss texting in her Peggy Olson costume! And much, much more (even the kids are in it, and there's even a blooper reel!). It's so great we're not even mad at the conspicuous absence of Christina Hendricks and Bryan Batt. See it here first!