These P.I.s will help you expose even the best of fibbers.

By Alissa MacMillan for Lifetimetv.com

It's the perfect first date: a glass of wine, light conversation, laughter and a polygraph test? When you first meet a guy, there are moments when you can't help but wonder if he's the real deal. So we went straight to the experts -- female private eyes who are experienced with the art of deception -- to help you become your own truth police. The ultimate defense? Your gut instinct. "You know the answer so much of the time," says Amy Gray, private eye and author of "Spygirl." Just in case, watch for the following clues:

He repeats your question. It's a red flag when you ask, "So, what did you do last night?" and your guy replies, "What did I do last night?" He's likely hiding something, say the experts. "Guys repeat a question to buy time and think of an answer," says Lynne Russell, private investigator and author of "How to Win Friends, Kick Ass and Influence People." The truth, on the other hand, will be readily on the tip of his tongue.

He avoids eye contact. It's the oldest tell in the book. "Take note when he speaks but won't look at you," says Janice Holt of Legal Legs investigative firm in Tennessee. Fidgety hands and shaky knees are also signals of agitation, adds Constance Marie, a private eye with Sherlock Investigations in New York. Of course, some men may simply be shy, while others might be well practiced at being dishonest. "A good liar can look you straight in the eye and lie up one side and down the other," warns Russell.

His talk is too big. He owns seven boats, runs a multibillion dollar company and just came back from climbing Mount Everest. The way to size up all that exaggeration is in the details, says Marie. "Ask inquiring questions," she says. If he won't give a more in-depth answer -- such as naming the firm -- there's reason to wonder.

He plays the first-name game. You've been chatting it up online and you two have planned a first date, but he's still "just Tim." Uh-oh. "If guys won't give you their last name, you don't want to meet them," says Marie. When he finally does tell you his surname, check him out: A Google search takes a few minutes. Marie recommends Web sites like Search Systems, which may cost a few bucks but do great background checks. And no, it's not being paranoid; it's being smart.

He won't let you meet his friends. You always want to corroborate what he's been saying, says Gray. "Meet their friends as soon as you possibly can and get a better sense of that world so you can trust him a little more," she says. "You have to be able to verify through other behavior, other actions, other people, other sources."

What he says and what he does don't match up. "If someone's telling you they love you but you don't quite believe it, ask yourself, What do their actions show?" says Gray. Does he treat you with respect? And take a good look at his everyday life: "If he says he graduated from Harvard and he's working as a house painter, check into it," she says. Sure, he might be a very well-educated house painter or he may not be the real thing after all.

His favorite phase is "No, tell me about you." Does he avoid talking about himself? Be wary: Most guys love to yak about themselves, especially when they're trying to impress. "When someone turns it back to you every time you ask something about them, they're hiding something," says Marie. Don't ignore your instinct: "When somebody is evasive, you have to believe there's a good reason for it," says Russell. The truth will be a straight answer.

He's always one step ahead. If he seems to think of things before you do -- where to eat, where to sit, what to order -- you may have stumbled onto a pathological case. "As long as he stays ahead of the game," says Marie, "he won't be caught off guard and won't be caught in a lie." This type of deceiver needs to manage his tangled web, so he maintains control over the relationship.

He's caught in a lie off the bat. "It has to be a one-strike-and-you're-out policy," says Gray. If you've only gone out a few times and you've already called him on a small fib -- even about what he did over the weekend -- then it's time to move on. "You're headed for trouble if someone barely knows you and they feel they need to lie," says Gray. "That means it's just the tip of the iceberg." The bottom line? Lose the liar and you'll improve your love life.

This article can be found at: http://women.msn.com/1063253.armx