Okay, so maybe the biggest party of the weekend wasn't the Super Bowl. Also, Sam Smith has a new rival for the title of "Most Popular British Male Singer Under The Age of 25."
Alas, there's no secret video footage of J Lawr singing "Happy Birthday" or breaking it down to "Best Song Ever." Still, the event didn't go entirely undocumented, with guests like Cara Delevingne, Kendall Jenner, Alexa Chung, Samantha Ronson, Rashida Jones, and Kelly Osbourne sharing snaps from the party. Photos were reportedly not allowed, though a photo booth was on offer.
Speaking of photos, all four of Styles' Sweet Lady Jane birthday cakes featured the pop star's mug. We know this because sneaky party guest Rita Ora flouted the no-photo rules and snapped a shot. Click through to see the saccharine goodness for yourself.
OPENER IMAGE: BEIMAGES/MATT BARON.