03/03/2008 at 01:00 AM EST
Who needs an Oscar when you already have the woman you adore with you on the red carpet? Avowed bachelor George Clooney
seems to be shelving his Oscars stag routine to share Hollywood's biggest night (he's a Best Actor nominee for Michael Clayton
) with his girlfriend Sarah Larson. The Las Vegas cocktail waitress is choosing from several vintage gowns and diamond baubles for her glam look (see box). As for Clooney, well, whatever tux he's in at the Feb. 24 Academy Awards, he'll likely be wearing something increasingly brighter on his sleeve: real affection for his steady—evidenced by their intimate Valentine's Day dinner at Vegas hotspot Nove Italiano. "They were hugging and kissing, toasting each other, acting very much in love," says an onlooker. As Clooney's Clayton
costar Tilda Swinton notes, "He is very happy at the moment."
How happy? "God knows—he claims he will never settle down," says Swinton with a laugh. And yet, there are signs of commitment: It has been months since Larson, 29, a native of Kent, Wash., has worked at the various Vegas nightspots where she earned her living before sparks flew with Clooney, 46, her longtime acquaintance, at the Ocean's Thirteen
premiere party in town in June. Instead, she has been at Clooney's side, whether resting her head on his shoulder during a break from a peace conference in Rome in December (he spoke about Darfur), holding his hand while he did press for Clayton
in Manhattan in January, or sharing close moments in Vegas in February. "She is such a sweetheart," says a source. "They are so comfortable together."
And then some. On Feb. 15, after a romantic Valentine's Day that included Cirque du Soleil's "Love" show, the two got down to friskier business: They watched topless showgirls during the Crazy Horse Paris show at the MGM Grand, slow-danced at the Palms Casino Resort Playboy Club (his head was often buried in her shoulder) and, at 1:15 a.m., retreated to their Palms suite, featuring an indoor waterfall and a round rotating bed with mirrored ceiling. As Swinton observes, "George is full of vim and vigor." Still, there is more between him and Larson than heat—there is heart. "He's her dream guy," says a Larson pal. "He's a gentleman. They make each other happy."