Have you ever experienced any of the following scenarios: having sex just to have sex; having sex without talking about what it means; having meaningless, alcohol-fueled sex; having sex with a friend, co-worker or someone from a social stratum different from yours; being sexually pressured or taken advantage of; having sex when only one person is emotionally involved?

By the time most single heterosexuals hit their early 30s, more than 90 percent of them will have had one or more of these encounters, concludes a study just published in the Scandinavian Journal of Sexology. Researchers even have a name for such scenarios: an unpleasant sexual encounter. And you thought it was just part of growing up.

This transparently obvious survey comes to us courtesy of the National Institute of Public Health in Oslo, Norway. The research team recruited 33 men and women from nightclubs in Oslo, and interviewed each person about his or her sexual habits. The results? Only three participants reported never having had a bad sexual encounter. The researchers also confirmed the findings of an earlier survey -- that people out looking for sex tend to follow a time-consuming and goal-oriented mental "script" of how the night should progress, and that this itinerary is idealized and mythical, and thus highly subject to failure.

"Sex is nonverbal communication about feelings -- but people fail to verbally communicate about what the sexual encounter actually means in terms of forming a committed relationship or simply sex for the enjoyment of sex," study author Bente Treen told a reporter from Reuters Health.

Treen acknowledged that people often feel enormous guilt after a one-night stand, and hopes that such research will help people understand what a quickie actually means.