Mary-Kate Olsen AshleyMK.jpgAh, to be multi-millionaires at the age of 21. Twins Ashley and Mary-Kate Olsen celebrated their joint birthday yesterday - making them finally legal to drink and what not - and word on the street is that MK bought a pricey necklace from Antiquarius for her lucky sister. Hopefully Ashley got something just as expensive pretty for MK! The girls met up at the fancy Chateau Marmont later in the night, presumably for dinner and a gift exchange.

Hope they had a fun birthday!