You know it's been a wild night when you can't keep your knickers under wraps! LOLz!
The singer went all out with her look, channeling the glamour of the 70s in her ostentatious outfit, teased-to-the-heavens blonde hair, and ultra glittery makeup!
Bianca Jagger and Donna Summer would be proud!
Rita also had a seksi Red Riding Hood vibe in her velour red Natalia Kaut dress with a plunging cowl neckline that doubled as a hood!
And doesn't her giant gray Diane von Furstenberg fur coat kinda make it seem like she killed the Big Bad Wolf and wore his pelt???
ANYWAY, the real story here is Rita's off-white undies being exposed thanks to that insanely high thigh-slit!
Happy birthday, girl!
[Image via Will Alexander/WENN.]