Britney Spears revealed herself to fans in Vegas when her leotard shifted around her chest ... but powered through it like a champ.
The nip slip went down Wednesday night at Planet Hollywood, where she made a hard right turn during a strut ... causing her left boob to pop out.
Ever the professional, she paid the wardrobe malfunction no mind for at least a good minute. Probably took a cue from Janet ... don't freak out.
Victoria's Secret Angel Stella Maxwell -- Miley Cyrus' old hookup chick -- either broke or embraced rule number 1 by rolling up to the Love Magazine party in London Monday night braless in full boob glory.
It's one way to stick out in a crowd that included Bella Hadid, Rocco Ritchie, Kate Moss, Courtney Love and Frances Bean, Cara Delevingne and Rosie Huntington-Whiteley.
Rita Ora put her love for the good ole U.S. of A. on full display ... on her nipples.
Ora fell 48 stars short of a true American flag salute after her Wednesday night show at the El Rey Theater in L.A. -- though we doubt she heard a single complaint about it.
Perhaps next time ... Rita can take a few pasty pointers from Miley Cyrus, who definitely wore them better last night on "Jimmy Kimmel Live!"
They are a party in the U.S.A.
Chrissy Teigen thinks nipples are like the Mona Lisa ... completely overrated.
Teigen ran into our photog in Bev Hills Wednesday, telling us why she "f**ked" with Instagram this week with her bare boobie photo assault.
Clearly, C.T. doesn't think lady nips are a big deal ... and vows even MORE social media toplessness in the very near future.
In other words, she's gonna milk this controversy for all it's worth.
The photogs were absolutely titillated to see Jennifer Lopez and Marc Anthony last night -- especially after she decided to play a game of peek-a-boob with 'em outside Cecconi's.
