PasterbackEven sleepy Sunday mornings can be star-spotting exercises in West Hollywood.

Hardly anyone recognized Ryan Seacrest, looking all incognito in a baseball cap, camo-shorts and urban Nikes, working out with his trainer at the Fitness Factory.

But the "American Idol" emcee’s bright shiny Bentley parked in the lot gave him away. Ego-mobiles outside usually mean overpaid celebs inside.

Another dead Seacrest giveaway: the buxom blonde  beard, er, babe that Seacrest always brings to the gym to make him look oh-so hetero.

Jewel was also pumping iron at the double F, looking way less crunchy granola than she used to, in sleek black leggings and a crop top, with her long blond hair pulled back.

The most disturbing celeb sighting at the trendy WeHo gym?

Top Hollywood personal stylist Jessica Paster, stuffed into a gangreen tank and low-slung crop sweats that kept sliding down to reveal her ass-crack as she worked up a lather on the treadmill.

To make matters worse, she was undie-less so every step gave an El Grande Boo-Tocks show to other gym dandies.

"Dude, that’s enough to make me lose my Sunday breakfast," said a horrified onlooker.

Told that the bare-bottomed babe gets major moola for dressing stars like Ellen Pompeo, Jewel, Angie Harmon, Thandie Newton, Diane Lane and Jessica Simpson for Hollywood awards shows and movie premieres, the observer was stunned.

"You’ve gotta be kidding," he said. "I wouldn’t let her dress my dog."

Let this be a lesson: Always wear underwear — even to the gym. You just never know who’s watching your back.

Photo Credits: Top Hollywood stylist Jessica Paster shows an unsuspecting young girl how to wear jeans (tighter!) at a Levi’s fall fashion event in Miami.
Rodrigo Varela/WireImage

Posted by:LATimes