LiLo rocked a tacky chic pink ruffled minidress and diamond necklace and was on the arm of her best gal-pal Samantha Ronson, who wore a tux and and her customary hat. Naturally.

The bash took place after a family dinner at Magnolia and featured a Marilyn Monroe-themed birthday cake and DJ AM and Ronson taking turns spinning dance and '80s tunes for guests that included Ali and Dina Lohan, Lindsay's little-seen brother Michael, Chris Brown and Jamie-Lynn Sigler.

Lindsay's flashbulb-loving mom made time to pose for the paps and greet guests outside, according to footage on TMZ.

Lez Lo was said to be kiss-kissing at the door of the ultraprivate—if unsponsored—fete, as Samantha hovered protectively with her hand on the small of Lohan's back.

Is it true love, or was Lindsay already drunk?

Actually, word is Linds abstained and contented herself with birthday prom cupcakes and Red Bull.

After she blew out the candles, she reportedly told guests to "shut the f--k up" when they asked for a speech.

Oooh, cranky—guess it was all the sugar.