"The French say Champagne should be drunk straight from a beautiful lady's slipper."

In this case, a fanciful figure of speech led to fact. The earliest mention I can find of an actual historical personage drinking wine from a lady's slipper is this one:

When sisters Ada and Minna Lester came to Chicago in 1899, they leased a three-story, fifty room double mansion here, refurbished it and opened the Everleigh Club on February 1, 1900 - it was the showplace of the Levee. Ada, 21, and Minna, 24, became famous as the Everleigh sisters. The mansion had an art gallery, a library, and a huge ballroom with chandeliers of cut glass and three orchestras. The bedrooms were lavishly decorated and sound-proofed, had marble in-laid brass beds, and there were always thirty of the most lovely girls on duty 24 hours a day. Prince Henry of Prussia reportedly visited the club in 1902. During a banquet in his honor, one of the girls' shoes flew off while dancing, hit a glass of wine and spilled some of the champagne into the shoe. A man nearby picked up the slipper and drank the wine from it. Almost on cue, the entire group arose after taking a slipper from the girl he was with, had the waiters pour champagne into them, toasted the Prince, then drank from them. Wine was sipped from a slipper for the first time.

Source: Google Answers

The vintage Mazourka (Masovia Women) or Mazurka (English)originated in the province of Mazovie, Poland near Warsaw and became itsnational dance in Poland's golden age (Sixteenth Century). Originally it wascalled the >Holubiec or >Holupca, named after the brass metal heels,which they strike while dancing. The Oberek, Polska and kujawiak are related.

The Mazurka issometimes called the >Masur or >Masurek by the people of Poland while itsname is derived from the tribe called "Masures" who dwell in what wasonce the Duchy of Masovia (Mazowsze.) From Poland it went to Russia and formeda Russian Mazurka with the soldiers then on to England in 1845 by the Duke OfDevonshire (1833-1908) and became nationalized in Paris, France and othercountries.

The Palantines invented the custom of drinking from the shoeof the dancer after dancing an extravagant Mazurka. The Gedrosian Prince hasbeen noted as drinking champagne from Taglioni's shoe after she danced aMazourka in a five act Ballet. The Mazurka is not at all like the version mostpeople have seen in the "Adams Family Movie" which made fun of thedance and its name.

Source: Street Swing Dance History Archives

It seems the custom began in different places around the world at different times and quite spontaneously. Despite the obscurity in origin, I personally love the idea of My slave or sub drinking champagne from My patent leather stiletto. As far as I am concerned, it really is the only way for a sub or slave to have the true privilege of drinking champagne when toasting My birthday in this manner *smiles*.