A little more than two months after they announced their split , Jennifer Westfeldt was spotted arriving at Jon Hamm 's home in Los Angeles. PHOTOS: Jon Hamm's best movie roles "With great sadness, we have decided to separate, after 18 years of love and shared history," they told People magazine. All eyes were on the actor to see if he would thank his then-ex, which he did, as well as his pet pooch, Cora .