Lindsay Back in Her Birthday Suit

7/3/2008 9:14 AM PDT

Lindsay Back in Her Birthday Suit

Lindsay Lohan had her '80s prom themed b-day last night -- and by the looks of Sam's strapping ensemble, Ronson was her date. Sam in a dress? Bitch, please!


Linds had din din at Magnolia followed by a low-key party at Teddy's in the Roosevelt Hotel, where our spies inside tell us the Birthday Girl looked sober all night, pigging out on cupcakes. The only celeb we heard about was Chris Brown -- and that guy left early.

Mama Dina was there too -- but no sign of Michael. He must have been too busy taking paternity tests.