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That cracking sound you heard on Sunday night? It was millions of devoted Justin Bieber fans simultaneously suffering a broken heart as he kissed girlfriend Selena Gomez on live TV at the Billboard Music Awards.

And while the ceremony was set in Las Vegas, the wholesome honeys kept things tasteful as they shared a quick lip-lock and equally decorous hug when Justin was named Top New Artist.

Of course, their restraint might have had something to do with the fact that Bieber's mom, Pattie Mallette, was seated next to Gomez, who was sheathed in a cut-out Dolce & Gabbana gown.

But their G-rated puckering still earned plenty of cheers from the crowd.

"I'm 17 and I want to thank God because he has blessed me so much," said the gold lamé-bedecked Justin, who collected five other awards at the ceremony.

When asked later if kissing his 18-year-old squeeze was the best prize of the night, Bieber sighed, "She's amazing," before adding that the highlight of the show "was seeing my mom's eyes and how proud she is."

Meanwhile, Justin and Selena, who made their official debut as a couple at the Vanity Fair Oscar party in February, enjoyed a more intimate night out on Thursday.

They were spied cozying up while watching singer-songwriter Ernie Halter perform in Costa Mesa, California.

Bieber even hopped onstage to perform Halter's song "Come Home to Me," which the teen-idol chart-topper recently covered and released via Twitter.


See the stars at the Billboard Awards

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Selena: I want to be in love

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