While Ava showed up with her mom, her escort for the night was Maharaja Padmanabh Singh , who People described as a polo-playing acquaintance of Prince William who grew up in Jaipur, India and is a member of that country's polo team. Oh, and he's also an actual royal, his official title being the Maharaja Padmanabh Singh of Jaipur. The two waltzed to a song from La La Land, which seems very fitting being that Ava's mom is Hollywood royalty.