It was the duet that was bound to happen.
But the big surprise came when…
Katy Perry joined him on stage for the end of his number. The packed house at the Palladium in Hollywood rose to their feet, applauding and cheering for the two.
"We love you," Perry said before blowing a kiss to the crowd.
Neil Patrick Harris also performed a duet—and locked lips!—with James Marsden. The two pieces of cuteness sang "An Old Fashioned Wedding" from the Broadway musical Annie Get Your Gun and ended the number with a sweet smooch.
Sarah Silverman wasn't so genteel. Jaws dropped during her mostly NSFW standup routine. She sang, too—an original ditty that ended with the crass-mouthed funnylady repeating the c-word about 40 times. Yes, 40!
The Trevor Project, a suicide prevention hotline for gay youth, honored Kathy Griffin and the Levi Strauss company at last night's shinddig. Also there were Chris Colfer, Jesse Tyler Ferguson, Josh Duhamel, Jessica Alba, True Blood stars Joe Maganiello and Kristin Bauer, Idina Menzel, Taye Diggs, Kate Walsh and Vampire Diaries' Ian Somerhalder and Paul Wesley.
Adam Shankman directed the production, which ended with Queen Latifah singing "I Know Where I've Been" from Hairspray.
Come back here later today to find out what Criss had to say about singing "Baby, It's Cold Outside" on tomorrow's episode of Glee.