Jon Hamm Jon Hamm

Call it puppy love. That's the best way to explain why Mad Men's Jon Hamm and his
longtime girlfriend, actress Jennifer Westfeldt, couldn't resist an offer to guest star on PBS' kiddie cartoon Martha Speaks. "They are dog lovers," says executive producer Carol Greenwald.

A chance meeting in an elevator with the show's head writer led to an offer to create an episode revolving around the couple and their German Shepherd mix, Cora. "The story was inspired by Jennifer saying how much she missed her dog," says Greenwald, who was beyond thrilled at how Westfeldt and Hamm got into the spirit of the show, which airs February 20. "I appreciated the enthusiasm they brought to this — they had to do a lot of silly things and say silly lines and they just pulled it off completely."

As for the "timid" Cora, her famous owners opted to have a voice-over pro do her lines. It's a dog's life!

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