Alec Baldwin Totally Transformed By 27-Year-Old Girlfriend Hilaria Thomas

Anyone notice Alec Baldwin lately? There's an extra spring in his step. He's visibly leaner, and his face is slimmed-down, too. He's smiling. A lot. He seems genuinely ... happy.

It's as if the famously moody, unpredictable, emotionally charged actor is a completely different person. Who's to credit for this remarkable transformation? Baldwin's new girlfriend, 27-year-old yoga instructor Hilaria Thomas. The "30 Rock" star, 53, is downright smitten: in his appearance on Letterman Tuesday night, Baldwin must have referred to Thomas as "my girlfriend" about 20 times. Meanwhile, the "Late Show" camera panned to live footage of the pretty brunette sitting backstage in the green room.

Thomas, whose first name is pronounced Hih-LAHR-ee-ah (or something like that), smiled coyly while her famous boyfriend gushed that he felt like he'd known her "on a spiritual level for years." Baldwin said he wanted to "travel the world with" -- wait for it -- "my girlfriend."

Man, he is whipped. The actor is SO into Thomas, he sold his fancy apartment on Manhattan's Upper West Side to move in with her downtown. According to Page Six, the couple even have promise rings signifying their love and commitment. Baldwin is proud to show off Thomas in public: on Sunday he brought her as his date to the U.S. Open opening ceremony in Flushing, Queens, where he kissed her in front of the cameras, grinning from ear to ear like a giddy schoolboy. In June, he took Thomas to the Tony Awards for their first major red-carpet debut as a couple.

Thomas, a former competitive dancer, teaches yoga at the Yoga Vida studio in New York. Whatever Zen magic she's working on Baldwin -- who, with all due respect, is the opposite of Zen -- has achieved refreshingly dramatic results.

Shocking 26-year age difference aside, Baldwin's newfound joie de vivre is infectious. We admit it: we're happy for the guy.

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