Don't tell Lea Michele!

On Saturday, her boyfriend and Glee costar Cory Monteith planted one on a different big-voiced TV singing sensation: Smash's Megan Hilty!

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Along with fellow Gleek Naya Rivera, Monteith, 29, hosted the 23rd Annual Gay & Lesbian Alliance Against Defamation (GLAAD) Media Awards at the Marriot Marquis in NYC. They nearly stole the show when they invited the highest bidders in a "kiss-off" to help raise funds for GLAAD's work for awareness of and support for the lesbian, gay, bisexual and transgender (GLBT) community.

In an unexpected move, John Stamos bid to kiss Monteith and ascended to the stage -- but the trio quickly decided to raise more funds by inviting a third bidder to smooch Stamos as well. The three winning bidders for the lips of Monteith, Rivera and Stamos coughed up $5,000 each.

Rivera gave her "sweet lady kisses" to a man who dipped her dramatically; Stamos, 48, smooched with a husky gentleman in a suit; Monteith kissed giggly, blonde Hilty, 30, who competes with Katharine McPhee for the spotlight on NBC's Smash.

Watch the video of the kiss-off now.