Jon Hamm tells Us Weekly he is still dating Jennifer Westfeldt after a recent report speculated whether he was dating Mad Men costar Elisabeth Moss. Credit: Dimitrios Kambouris/Getty Images

False alarm, people… Jon and Jen are doing just fine! Jon Hamm updated Us Weekly on his relationship with longtime flame, Jennifer Westfeldt, at the L.A. premiere of Million Dollar Arm Tuesday, May 6. His chat follows a report that questioned whether Hamm was secretly dating his Mad Men costar Elisabeth Moss.

"Unfortunately Jen can't be here tonight," Hamm, 43, told Us of Westfeldt, "because she's on stage in New York City." (Westfeldt, 44, is currently starring in an off-Broadway production of Too Much Sun.)

The AMC star added that although his relationship is currently long distance (with Hamm in L.A.), the couple makes it work! "I'm back [in NYC] every two weeks. So I pop back and forth," he explained of his bicoastal lifestyle.

Indeed, a source close to the actor said the report about a supposed Hamm-Moss fling was "crazy." The insider added, "He's been in New York a lot supporting Jen."

On Hamm's relationship with Moss, the source told Us: "They are good friends…they have been on the same show for years." A second source added of the costars, "They are the best of friends, but never would I expect anything romantic. They are like family."

Hamm's onscreen love in Million Dollar Arm, Lake Bell, gushed to Us about Hamm and Westfeldt. "They are the best couple," Bell told Us in a recent intervew. "He's crazy supportive of her and loves her incredibly." The Friends with Kids costars have been together since 1997.

Though Westfeldt was unable to make the premiere of her boyfriend's new movie on Tuesday, Hamm was still supported by Mad Men cast members, including his onscreen daughter Kiernan Shipka.

"It's nice when I see friends coming to support," Hamm told Us. "It feels good."

Pick up the new Us Weekly for our exclusive sit-down interview with Million Dollar Arm stars Hamm and Bell -- out now!