KENNEWICK -- Police busted three woman for prostitution in a late-night sex sting.

Kennewick Ppolice spent two months setting up the sting after responding to erotic on-line ads on Craigslist that offered more than just a backrub.

Police said this is the first time they've nabbed naughty girls from the popular website, but investigations revealed prostitution happens a lot.

If you browse the "Services" section looking for a massage, you very well may get more than you bargained for.

Action News does want to warn you: this is a mature topic.

Erotic massages, strip teases, dirty dances.

Any salacious offering is just one click away: Craigslist.

It's all there front and center, but it took a tip to lead Kennewick Police to the site.

Officers found women blatantly advertising prostitution.

Investigators claim advertisers often use code words or abbreviations to offer their sexual services, such as ads that read "FS" for Full Service.

"I believe that means they have sex with the person who calls," said an erotic advertiser on Craigslist who wanted only to be identified as "Rory."

"Rory" posts ads regularly on Craigslist and told Action News she only offers massages.

She doesn't expect to be caught because she isn't doing anything illegal.

"A lot of people assume, a lot of people call without reading the ad," she said. "I've had to turn away more people than I've ever accepted because they want prostitution and that's not what I do."

Police picked a hotel and undercover detectives rented a room.

They phoned three suspected call girls, requesting their services.

Each showed up alone.

And this time it was the girls who got more than they bargained for.

Police arrested 21-year-old Rebecca Bunten, 29-year-old Marion Aragon and 32-year-old Gina Lund for prostitution and operating a business without a license.

"It disgusts me," Rory said. "Because I think you shouldn't do it."

Police also swiped marijuana and prescription drugs off two of the girls.

all the girls were booked and released.

Police said the women could face felony charges for the drugs.

KPD said prostitution often brings other crime like theft, robbery or drug abuse.

They said unassuming clients are often victimized as a result of hiring a hooker.

The case is still ongoing.

Cops said there are several other women and men out there they are investigating.

Kennewick Police told Action News they regularly check to make sure online businesses are actually selling what they are offering.

Police warn: if you're offering "services" without the right paperwork, you could go to jail.

Kennewick Police would not name the hotel since they're the ones who set up the operation, and they didn't want to ruin the hotel's good name.