Whenever she hits the beach, Sienna Miller seems to have wardrobe malfunctions that reveal more than expected. After showing the paparazzi her coin slot when on holiday with beau in Mexico, Sienna flashed the photographers again in California the other day, when the ocean's powerful waves washed her skimpy bikini top off her breasts.

The actress raced into the waves to cool off after lounging in the sun but the strapless bikini top didn't seem to wanna follow her, slipping down around her waist. But the British starlet quickly realized her moment of over-exposure and pulled her top up and returned to the sand. She isn't the only Tinseltown star to have pulled that off though, as Kirsten Dunst has also experienced a similar malfunction while sporting a skimpy strapless top as well.

Although Sienna is no stranger to baring flesh - she filmed nude scenes for her upcoming Hippie Hippie Shake set in the Swinging Sixties and appeared topless in Alfie, co-starring Jude Law - showing off intimate body parts without any cameras around is not exactly the actress' favorite thing. After the nipple-revealing incident, Sienna met with her fiancée, Rhys Ifans, for a sushi feast at Nobu, in Malibu, where they were both fully dressed.

The couple have been inseparable since they have started dating, enjoying a string of luxury holidays, including a trip to Mexico, and joining one another on the sets of the films they are working on. Sienna was previously in Prague, filming the action movie GI Joe, while Rhys was working on Richard Curtis' new movie, The Boat That Rocked Southampton, and when they weren't talking endlessly on the phone, the two were booking flights to see each other, even if for a very short time.