How did Usher end up with Tamara Mellon at the Costume Institute Gala on Monday night? The singer, who is rumored to be dating Island Def Jam executive Grace Miguel, escorted the Jimmy Choo founder to the event and the after- party at the Mark Hotel.

VIDEO: CELEBS CELEBRATE ‘AMERICAN WOMAN’

PHOTOS: BEST, WORST & WEIRDEST AT THE MET GALA

PHOTOS: MET GALA RED CARPET

PHOTOS: MET GALA’S MOST MEMORABLE MOMENTS

MORE: A-LISTERS STYLING AND BEGUILING

MORE: OVERSEXED IN THE CITY

A source close to Usher said the pairing happened at the last minute. “Usher was supposed to be in Australia at the time, but his whole European schedule changed in part due to the Iceland volcano tying up travel abroad. He wanted to attend, and was invited to sit at Mellon’s table. The two had met socially before, but are not good friends.”