Not Nude: Katie Rees Wears Bikini at Birthday Party

File this among The Most Disappointing Happenings in Hollywood, right along with those supposedly naked Amy Polumbo photos.

We should've known that we couldn't have counted on that beauty queen to bare it all, but what's Katie Rees thinking in the accompanying pictures from her 23rd birthday party over the weekend? It was held at a topless pool!

Yet somehow, Katie Rees - a raunchy gal who is best known for naked, lesbian pics - couldn't even take off her bikini top. For shame.

Rees and friends rocked out at the Bare Pool Lounge at the Mirage yesterday afternoon. Based on the evidence included here, though, there was more nudity in the Mary-Louise Parker Weeds ad than during these festivities.

This was a major letdown and we're afraid of what will happen next. Might Spencer Pratt be heartfelt and understanding on The Hills season premiere tonight? Perish the thought.

When it comes to birthday suits, however, at least we have Keira Knightley nude to ogle over now.