Rihanna Stays Stone-Faced in Scarlet

For someone with such a fiery hairdo, Rihanna appeared quite subdued last night on her way to party it up for boyfriend Matt Kemp's birthday. Under her scarlet wig, RiRi maintained a somber facial expression as she headed into Drai's nightclub in L.A. Maybe she knows it might not live up to the fun she had at Katy Perry's bachelorette party last weekend?

OK! GALLERY: RIHANNA TAKES A BREAK FROM THE CITY OF ANGELS FOR A LITTLE FUN IN SIN CITY

Rihanna is a bridesmaid in Katy's upcoming nuptials, and she and the other gal pals really lived it up in Las Vegas last weekend!

OK! NEWS: RIHANNA HELPS KATY PERRY CELEBRATE HER BACHELORETTE PARTY IN VEGAS

They hung out at the Hard Rock Casino & Hotel, lounging in the pool, eating and, of course, drinking a few toasts to the bride-to-be! Maybe Rihanna got some ideas for her future!