Ahoy! Never one to step out of the house in sweats (unless they're the bubble-gum pink velour variety), Paris Hilton donned a barely-there sailor costume while Halloween shopping this week.

The blond heiress, who recently launched a Marilyn Monroe-inspired perfume, was snapped by paparazzi while shopping at L.A.'s aptly named Trashy Lingerie shop, which stocks items like the $400 Alice in Undie Land costume and the naughty lamb-clutching Bad Peep outfit for $350.

Although most folks don't shop for Halloween costumes while wearing a costume, Hilton did just that, sporting a sexy white-and-navy-striped bustier, navy hot pants trimmed with brass buttons, fishnet hoisery and a jaunty sailor cap while she scanned the store's aisles from behind her oversized shades, holding a few keepers in her hands.

Knowing how much the socialite likes to party, it's no surprise that she couldn't wait until next weekend to start celebrating the holiday -- or that she'll need more than one costume for the occasion.