Alex Rodriguez and Kate Hudson's Backstage Make-Out Session

Alex Rodriguez and Kate Hudson heated things up backstage at the American Music Awards last night.

A Rod was in Los Angeles to help introduce his friend Jay-Z's performance with Alicia Keys of the New York-centric anthem "Empire State of Mind." Hudson was on hand—rocking a low-cut vintage Versace chainmail dress that continuously threatened a wardrobe malfunction—to introduce her Nine costar Fergie and the Black Eyed Peas with Nicole Kidman, who also has a starring role in the Rob Marshall film.

But it was the backstage antics that had tongues wagging. A source tells people.com that the couple were caught making out behind the scenes. "A-Rod gave Kate a big squeeze to keep her warm," says the insider, "and a sweet smooch." Hudson was, "beaming, glowing actually," adds the source. We don't know what is more daring, wearing a chain-link dress, or dating a confirmed lothario like Alex Rodriguez!