Think your husband or wife may be making whoopee at the annual holiday office party? You can hire a private eye from a Mt. Clemens-based firm to go to the party undercover and make sure your spouse isn’t getting into more than the holiday cheer.

Advanced Surveillance Group, a private investigation firm with offices in several states, says holiday work parties are rife with opportunities for sexual trysts. ASG cites several surveys, including a 2005 poll by Men’s Health magazine in which 44% of the men interviewed said they “hooked up” with a coworker at a holiday office party.

“We hear a lot about these relationships launching at holiday parties,” ASG partner Paul Dank said Thursday. “A couple of coworkers spend a lot of time together at the office and then they go to a party, let their guard down and drink too much. It’s a festive time, and people’s inhibitions are lower.”

About 90% of U.S. companies say they’ll have parties this season, from expensive bashes to casual potlucks. The parties reward hard work, raise morale and give bosses and mail clerks a chance to raise a glass together.

But the parties also create concerns for employers. In a 2006 poll by career information Web site Vault.com, 38% of respondents said their coworkers “typically fool around” at the office party. That’s bad news for companies because sexual trysts among coworkers can cause nasty gossip, break up marriages, divide staffs and make it tough for the couple to work together.

Worse, when the sexual advances are coerced or unwelcome — or perceived to be — the party can become “a breeding ground for sexual harassment claims,” says the National Federation of Independent Business, an advocacy group for small and independently owned companies.

“We handle a lot of sexual-harassment lawsuits,” said Pat Nemeth, partner at Nemeth Burwell, a Detroit-based employment law firm.

“It’s still considered a working environment and anything you say can and will be used against you.”

Claims arise from comments made when someone from work gives you a ride home, or from those overheard at the bar, Nemeth said.

Even if you don’t expect a private eye to follow you to your holiday party, watch your conduct. Despite the lights, the food, the open bar and Santa sightings, holiday parties are about work. They can be volatile because they combine people who can make or break your career with workers who may be deeply into the holiday spirit(s).

The wrong move, attire or comment can embarrass you, affect your job future or expose you to harassment complaints, criminal charges or divorce court.

So before you don your red velvet dress or tuxedo, here are some tips on conduct and etiquette for office galas big and small:

When the party rolls around, do not …

• Pass up the invitation, unless you’ve got a darned good excuse. Collegiality is valued by companies, and you don’t want to be found lacking. And don’t rudely drop in for 10 minutes and then split. Stay a while and socialize, but don’t be the last to leave either. (It makes you look needy.)

• Wear flashy or revealing duds. No John Travolta disco suits. No breast-baring necklines. Ask what the proper attire is. Be safe and go for conservative party clothes.

• Bring a gag gift. No lampshades whoopee cushions, dribble cups or any similar items for the boss. She’ll laugh, but she won’t really appreciate it.

• Make inappropriate toasts. And remember the “Seinfeld” episode in which Elaine does that weird, thumb-jerking dance? Don’t do that, either.

• Talk work, gossip, monopolize the conversation, gripe about the boss or blow off steam. Be gracious. Show an interest in others. Thank them for their hard work and friendship.

• Drink to excess. In a recent national survey by Vault.com, participants told about a man who threw up all over himself at the boss’ house, then grabbed the boss’ wife by the buttocks. Imagine explaining that the next day.

• Flirt. At the least, it can feed office gossip. At the worst, it could lead to something you’ll regret. In a 2005 news release, ASG told of a Grosse Pointe woman who hired the firm to watch her husband at the office party. Hubby flirted with a company saleswoman. When the party ended, the two slipped into a restroom and had sex. The private eye heard it all, then videotaped them coming out of a stall, dressing and laughing.

But do remember to …

• Mingle. Share your good cheer with as many coworkers as possible.

• Keep your hands to yourself, except for a handshake or a brief hug for friends. With federal laws and multimillion-dollar settlements, companies are tough on sexual-harassment complaints. The laws apply at office parties, too. In a new national survey by Vault.com, 25% of human resources directors said they disciplined an employee for inappropriate holiday party behavior.

“The best way to handle this is to be proactive,” said Robyn Marcotte, senior vice president of talent at the Pleasant Ridge online-marketing firm ePrize. “We have a big blowout in the summer and we are very clear upfront that it’s important to have a great time but you don’t want to be the person that’s talked about the next day.”

She said she doesn’t recall an incident in which an employee was disciplined, but she said that is not the worst consequence of behaving badly.

“The suffering from a peer-group perspective, the damage to your reputation, is much more severe and painful than the official ruling that could happen from a department standpoint,” she said, adding that ePrize tries to address problems before the opportunity arises.

• Network with people who can influence your career. Introduce yourself to superiors you might not know or don’t see every day. But don’t be smarmy.

• Say thank you. Thank your hosts and coworkers who planned the party. Send a thank-you note later.

• Have fun! Employers spend a lot of money on gatherings and, in these tight economic times, it may be the only gift you get from them.