An alarming new study published in the International Journal of Sexual Health reveals that casual sex, the practice of engaging in frequent, spontaneous sexual encounters with new and exciting partners, may only provide unimaginable pleasure and heart-pounding exhilaration for, at most, 25 to 30 years. 'People who choose to participate in random, no-strings-attached lovemaking sessions with sexually adventurous strangers should be advised that this type of behavior is only incredibly liberating for the first quarter-century or so,' said Dr. Loren Sullivan of Yale University, who coauthored the study on the long-term side effects of living out one's wildest fantasies on a semi-weekly basis. 'Though sometimes it can be longer.' This couple may be having fun now, but there could be cause for regret a quarter-lifetime later, researchers say. The study observed 100 sexually active volunteers who were not tied down by dull, passionless relationships and were therefore able to have sex with whomever they wanted, whenever they wanted. A control group of individuals who were married or had otherwise allowed their erogenous zones to fall into complete and utter numbness was also monitored for comparison. Researchers found that those who regularly achieved mind-blowing orgasms without the expectation of commitment often experienced mild feelings of loneliness and a passing regret after as little as three decades of pure physical bliss free of emotional complication. 'There's a troubling number of adults who spend their prime sexual years in complete coital abandon, then have nothing to show for it but dozens upon dozens of highly detailed erotic memories,' Sullivan said. 'They must be so empty inside, one would think.' Other common, albeit latent, secondary effects noted in the study include mild disappointment and mid-afternoon crankiness, as well as a lingering need for additional casual sex. Researchers could not conclusively establish a link between anonymous, passionate trysts in nightclub bathrooms and these results, however, as a large portion of the polling group was found to be asymptomatic. One participant, California native Greg Pertzborn, told researchers he sometimes wonders if the 30 years he spent beneath a different gorgeous woman every night were worth the periodic flickers of gloominess he began experiencing at the age of 59. 'When I think back on the countless times I've had raw, almost bestial sex, indoors or outdoors, with one, sometimes two Asian women whose parents I'll never have to meet, I occasionally get a little down,' Pertzborn said. 'God, what if I wasted my life having guilt-free, uninhibited, sensually explosive sex with anyone I wanted?' Sullivan and his team plan to continue the study, saying they expect to find that the unattached, sexually satisfied persons between the ages of 20 and 30 whom they have been monitoring will feel compelled to settle down with a single partner and begin discussing joint checking accounts 'any day now.' 'Tragically, it's quite possible that many of these singles may never realize how miserable a lifetime of phenomenal, kinky sex can make them,' said Sullivan, adding that recent evidence suggests such a healthy, rational realization could be further hindered by the experience of spontaneous oral sex behind the bushes at poolside cocktail parties. Although the study has not yet caused any perceptible reduction in the popularity of having casual sex, proponents of the report, like husband and father-of-four Howard Kehoe, say it provides proof that promiscuity is not 'the endless carnal thrill-ride' it is often made out to be. 'I am so thankful that I never acted on my natural impulses and engaged in a sweaty, toe-curling, life-affirming romp with that knockout I saw in the park last week,' Kehoe said. 'I may die having only caressed the naked, goose-pimpled flesh of two women on the entire planet, including my wife, but at least I know I'll never have to endure a burst of fleeting regret long after I've retired.' 'That's one sensation I never want to experience,' Kehoe added. 