It's Lindsay Lohan's birthday and she'll change her outfit FIVE times if she wants to.

The troubled actress celebrated turning 23 (she doesn't look a day over 45!) next month with a premature party around the pool at Wet Republic in Las Vegas.

But the bash – which included birthday cake that the skinny star actually ate – turned into a fashion show as Lindsay flaunted her bony frame in a number of midriff-baring outfits.

At one point, she pulled her fedora down over her eyes and mimicked a trademark Michael Jackson pose.