It rarely ever feels like Christmas in Los Angeles, unless of course you’re James Corden and you assemble a chorus of carolers that includes all of your famous friends. As has become his annual tradition, Corden got all of the year’s best Carpool Karaoke guests — Kelly Clarkson, Bruno Mars, Sam Smith and Fifth Harmony, Miley Cyrus, Pink, etc. — to sing “Santa Claus Is Comin’ to Town†led by Corden and Reggie Watts. You better not pout. I’m telling you why: Because Harry Styles will probably go in for a big ol’ smooch, as Corden now knows. But only if you call him Harold. Oh yeah!