Sydney Sweeney just proved she's got girlfriend-of-the-year credentials ... throwing a star-studded early birthday bash for boyfriend Scooter Braun . The "Euphoria" star surprised the music mogul with a massive celebration Saturday night in Santa Monica ... drawing a guest list packed with big names, including Jessica Alba , Tom Hanks , and Rita Wilson ... plus a guest performance from Warren G !!! A basketball hoop was set up for guests ... with the couple seen rocking matching Connecticut