Paris Keeps Private for Once—What's Up?

The socialite throws her boyfriend a private birthday party--but why so private all of a sudden, Paris?

Just like we exclusively told ya last week, Paris Hilton threw her BF, Doug Reinhardt, a surprise B-day bash at her Beverly Hills home last weekend, complete with stripper-esque cake popping on Par's part.

"It was a masquerade theme," our inside-the-party eyes say, and according to the always fab Page Six, Reinhardt "had no idea about the party and was so happy."

Does this mean Dougie doesn't read the Awful Truth? Guess we don't have to worry about hurting his poor li'l feelings in our blolumn!

It might look like P.H. is being the precious GF, throwing her boy-toy a B-day bash, but something is seriously fishy with this couple's romance redux...

"She's really not ready to reintroduce herself as dating Doug again," says our insider, who's très close to the empty-headed pair. "They're open about being back together, but since when does Paris throw a private party with no red carpet and not tell anyone?"

Totally right. Hilton ain't the type to keep anything on the DL, ever. This gal makes public announcements every time she goes shopping!

So what the ef's up? Does this mean she's just not feeling D.R. this time around and is merely going through the motions, or does she not want the press to sink its teeth into her men anymore? We bet Doug's disappointed he didn't get a photo op or an Us Weekly spread out of the secret soiree.

For us gossip mavens, the best part of the whole hush-hush shindig was that Hayden Panettiere was one of the few guests—and this wasn't her first fete at Hilton's house.

How come we never see these two gal-pals out on the street hanging together? Does Hay-doll not want to be associated with heavy partier Paris? That wouldn't be so great for her dolphin-saving, do-gooding image, would it?