Sharon Stone showed her 54-year-old lady bits on the red carpet last night -- and we doubt it was a "wardrobe malfunction."

The "Basic Instinct" actress, who has always loved showing off her body, stepped out bra-less to the amfAR Inspiration Night show in Paris on Thursday -- while wearing a see-thru top that fully exposed her breasts.

Sure, she's in Europe and the still-gorgeous star has never been modest ... but do you think the outfit is sexy or tacky?

And check out more stars who don't their age in the gallery above!