Her hair looks unwashed. Her heavy eye makeup is often smeared. And her clothes? Well, they're far more trashed than tres chic.

She's a "Dirty Girl". To many men, that means undeniably hot. Dallas resident Dan Williams says, "Independent like that, kind of bucks the convention, something that's just not the norm. I find that kind of attractive."

Oozing sex appeal is one of the first things the 27-year old Williams noticed about his now-girlfriend. She didn't want to be identified, but talking to us wearing in skin-tight clothes and high heels, she was unapologetic about her un-squeaky-clean appeal. She says, "Even negative attention is still attention and it still gets you further in life."

Take celebs like Lindsay Lohan, Taylor Momsen or the Olsen twins, for example. Dallas psychologist Dr. Ray Levy says the appeal to a man understandable and simple, "The attraction is it's always available." He says the Dirty Girl feeds a man's desire to be needed, wanted and potent. Guys have long been hard-wired to conquer, whether it's money or women. Dr. Ray Levy says, "One of men's dreams is the omni-available woman or the always present, always interested in sex female. It makes us feel very valuable."

Dr. Levy says one thing the Dirty Girl is not, however, is a poster child for long-term relationships. Dallas resident Michael Huynh says, "You're afraid, but at the same time you can't help but give it a try." But for guys brave enough, the risk may well be worth the sexy reward.