Sienna Miller seems to have the worst luck when it comes to exposing her breasts to the world at large, voluntarily or not. The British actress is no stranger to on-camera nudity, and she definitely doesn't come across as being too shy or reserved when it comes to flaunting her body and getting into skimpy bikinis when need arises. However, if on previous occasions we might have talked about Sienna Miller nipple slips, this time it wasn't as much a slip as a nipple invasion - just have a look at the photos and you'll see what it's all about. Sienna has been enjoying a string of luxury holidays in recent months, and is currently in the States with her boyfriend, Welsh actor Rhys Ifans. It was there that Sienna's most notable... ahem, nipple slips to date happened.

The actress was obviously thrilled to be on the beach, enjoying the sun and the sea in the company of another female friend. However, Sienna's enthusiasm and her energetic encounter with the waves caused her already skimpy bikini top to slide down and expose her boobs. Later on, the actress probably assumed that since the harm had already been done, she might as well have some more topless fun, and gave up the top completely for a little bit of ultra-hot sunbathing. If only more Hollywood actresses would adopt Sienna's life philosophy, what a wonderful world this would be for photographers and paparazzi everywhere. One tiny nipple slip, and off with the top - no additional fussing and bitching around - just kidding.

There is one (rather more serious) lesson to be learned from Sienna's little mishap, namely that even ladies with smaller boobs should pay attention to the kind of bikini top they decide to put on, as there's no guarantee the waves won't rip it off and expose rather more than initially intended. Judging by the photos, however, Sienna herself remains quite forgetful of the fact that the whole world just became better place for the male species. In any case, no one can now deny the British actress has great boobs, as irrefutable evidence is staring everyone right in the face.