The Smokin' Hot Olsen Twins

When not sporting oversized sunglasses or visiting Starbucks, Mary-Kate and Ashley Olsen also find a little time to run their billion dollar corporation entitled Dualstar Entertainment Group. And by a little time we mean once a month.

TMZ has learned that the 20-year-old media titans and some-time NYU students, come into Dualstar's Culver City, Calif. offices around every 30 days.

But instead of attending executive meetings or going over financial reports, the doll-like duo prefer to hole themselves up in an office and chain smoke cigarettes for hours at a time.

Besides being an appetite supressant and bad for you, according to California law smoking indoors in public places also happens to be illegal.