Justin Bieber locked in on Billie Eilish and delivered the moment everyone's talking about at Coachella Weekend 2 ... serenading the pop star mid-set and sending the crowd into a frenzy. Bieber launched into "One Less Lonely Girl" and made Eilish the clear focus, turning the performance into a full circle scene between the global superstar and one of his most famous fans. SZA joined him under the desert lights for a sultry "Snooze" duet, while Sexyy Red injected high energy into "Sweet Spot."