Some people assume their parents’ sex lives have been a real snooze ever since the single act that brought them into being, but a survey in the New England Journal of Medicine puts that childhood fairy-tale to bed. Most Americans not only have sex more than once in their lives, but they continue to have sex well into their golden years.

The U-S Census Bureau estimates that more than 300 baby boomers turn 60 every hour. If the prospect of sexual abstinence among America’s free-spirited flower children seems unlikely … it is.

The study finds that 73 percent of men and women in their late fifties and early sixties engage in sexual contact more than once a year. And 26 percent of the oldest age group studied … 75- to 85-year-olds … were still at it as well. Point being, make sure to knock before you stroll into Grandma and Grandpa’s house.

But sex after 60 doesn’t come without its own set of problems. Only a fraction of men reported using Viagra or other drugs to enhance performance, but more than half the study participants suffered from at least one sexual complaint. And because older couples often forgo contraceptives, the number of AIDS cases has skyrocketed among the senior set. The Centers for Disease Control and Prevention estimates that Americans over age 50 will comprise half of all AIDS cases by 2015. Rates of other STDs, namely chlamydia, gonorrhea and syphilis, are also on the rise among adults over age 45.

Growing older doesn’t mean growing numb to basic human cravings like hunger, thirst and sexual desire. Au contraire, sexual satisfaction can extend well into the twilight years. Consulting a physician can help older couples ensure that sex keeps getting better with age.