Mary-Kate Lights Up After Sneaking Out Of Madeo

Tsk, tsk, Mary-Kate Olsen!

The fashion designer/actress held on tight to a cigarette as she got into the back of an SUV Tuesday night. Mary-Kate, 25, had just snuck out the back door of one of her fave hot spots -- Madeo in West Hollywood -- but she didn't go unnoticed.

Mary-Kate was just on the East Coast last week to celebrate Fashion Week in New York City. According to Us Weekly, the former Full House star did everything she could to avoid Lindsay Lohan at last Wednesday's V Magazine party at the Boom Boom Room. After Lilo was sat at Olsen's table, MK went as far as asking the hostess to sit her at another table ... but none were available!

Ouch!