Absence doesn't always make the heart grow fonder, as Lea Michele learned the hard way when she split up with Broadway star Theo Stockman in September 2011.

Fortunately for the Glee actress, 25, dating costar Cory Monteith, 29, eliminates that problem. "They had a great little quick trip in New York," a source tells Us Weekly of the couple, who were spotted around the Big Apple over the weekend. "Lea didn't want to be away from him for just those few days."

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The couple took their romance public in February, though "they've been hooking up for a while," an insider told Us last month.

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Being with Monteith is bringing out the best in Michele, who visited her new beau's Vancouver hometown on February 25.

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"Cory is definitely having a positive effect on Lea. She's much less miserable these days," the source tells Us. "Even when she was with Theo, she was always depressed being so far away from him and not getting to see him. She likes having someone with her that's actually there. Long distance is not her thing."

Tell Us: Will Lea Michele and Cory Monteith's relationship last?

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