Along with a seemingly endless string of harassment and discrimination scandals, Silicon Valley’s homogeneity has a more trivial side effect: boring holiday parties. A fete meant to retain all your talented engineers is almost certain to wind up with a rather same-y crowd, made up mostly of guys. At this year’s holiday parties, however, there’ll be a surprising influx of attractive women, and a few pretty men, mingling with the engineers. They’re being paid to.

Local modeling agencies, which work with Facebook- and Google-size companies as well as much smaller businesses and the occasional wealthy individual, say a record number of tech companies are quietly paying $50 to $200 an hour for each model hired solely to chat up attendees. For a typical party, scheduled for the weekend of Dec. 8, Cre8 Agency LLC is sending 25 women and 5 men, all good-looking, to hang out with “pretty much all men” who work for a large gaming company in San Francisco, says Cre8 President Farnaz Kermaani. The company, which she wouldn’t name, has handpicked the models based on photos, made them sign nondisclosure agreements, and given them names of employees to pretend they’re friends with, in case anyone asks why he’s never seen them around the foosball table.

“The companies don’t want their staff to be talking to someone and think, Oh, this person was hired to socialize with me,” says Kermaani, who’s sending models to seven tech parties in the same weekend.

While this sounds crazy after a year packed with harrowing stories of sexual harassment, abuse, and discrimination—a tidal wave that started in San Francisco, with Uber Technologies Inc.—it’s part of an older trend. Tech companies have long used models to run their booths at trade shows such as CES in Las Vegas, hype up crowds at product launches, and direct foot traffic at conferences. That said, this year’s record-setting requests for the minglers, known as “ambiance and atmosphere models,” are a step beyond what the industry has seen before, says Chris Hanna, who’s run TSM Agency since 2004 and counts among his clients “one of the largest search engines in the world.”

“Traditionally, if I go back, say, over the last five years, if people requested these types of models, it was more for specific responsibilities,” Hanna says. “ ‘Be a hostess.’ ‘Show them the elevator.’ Now they’re trending more toward the fun, the atmosphere.” That includes costume parties, he says. So far this year, his models have been asked to dress up in outfits based on The Price Is Right and like Elizabethan nobles or forest nymphs to accommodate a slightly confused medieval theme.

The agencies say clothing stipulations help them screen for ulterior motives. Olya Ishchukova, chief executive officer of Models in Tech, says she frequently rejects company requests for cleavage and short-shorts. When a client recently asked for Pink Panther-themed latex bodysuits, “I pretty much explained to him that this is not what we do—and that could actually hurt his business” if the public found out, she says. She turned down the gig.

Ishchukova says she prefers not to send models on atmosphere jobs without specific tasks such as checking coats or serving food. Such tasks help remind everyone “they’re there for work, and nothing extra is going to happen,” she says. Hanna’s agency is among those with a zero-drinks rule for models on the job. Most models’ contracts say they won’t exchange contact information with party guests, and that gets tougher to handle with grace when they’re legally bound to pretend they’re guests, too.

The guests, of course, are generally less restrained. Holiday parties have featured prominently in several harassment stories in recent months. As Bloomberg reported in November, prominent venture capitalist Shervin Pishevar allegedly slipped his hand up the leg of Austin Geidt, Uber’s then-head of global expansion, at the company’s 2014 holiday party. (He’s denied the allegations, and Geidt didn’t comment on them.)

Vox Media Inc. is limiting employees to two drinks apiece at its Dec. 12 holiday party to curb “unprofessional behavior,” but so far it’s the exception. Cre8’s Kermaani visits the startups herself to get a read on the environment and her models’ safety. “If somebody is creepy toward me, and I’m the owner of the company, I can guarantee they’ll be creepy to the models,” she says. “Silicon Valley doesn’t have the best reputation.”

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