Want to guard against unplanned pregnancy and STDs? Well, a condom is the answer to that—but lots of guys aren’t wrapping it up.

The most recent National Survey of Sexual Health and Behavior found that less than half of men ages 18 to 24 used a condom with their last sexual partner. And the disregard for protection seems to get even worse the older you get: Only about 30 percent of men 25 to 34 used a rubber with their last partner.

Now, a survey of 2,000 Americans and Europeans from Superdrug Online Doctor, an online pharmacy in the U.K., provides further support for that trend. About 65 percent of Americans report having unprotected sex, and of that group, nearly 30 percent of them never use a condom during sex, the survey found.

That’s a problem: STD rates are higher than ever—but consistently using a condom correctly is nearly 100 percent effective at preventing transmission of diseases like gonorrhea and chlamydia, according to the Centers for Disease Control and Prevention (CDC).

Plus, STDs aren’t the only thing you might worry about. When used correctly, condoms also help prevent unintended pregnancies, the CDC says. Yet, of the study participants who said they’d be “devastated” by a pregnancy, 1 in 5 of them engaged in unprotected sex every time. So even though they desperately want to avoid a pregnancy, they aren’t taking the measures to avoid it. (Here’s why “pulling out” as birth control is so risky.)

So if condoms can help you avoid nasty infections and premature fatherhood, why have men stopped using them?

There are a couple of theories, says Debby Herbenick, Ph.D., a sex researcher at Indiana University. Younger guys often view condoms as just a birth control method, and might be unaware of how important they are for STD prevention. On top of that, many guys are influenced by porn, where condoms are hardly ever worn, she explains.

If you’re currently having casual sex with multiple people, you’re better off wrapping up with a rubber until you feel comfortable with your partner, Herbenick says. Once you’re in a long-term relationship—and pregnancy is the only concern—talk to your partner about looking into other effective birth control methods if you can’t stand the way condoms feel.

Until then, finding the best-feeling condom and using a little lubricant (we like this one from the Men’s Health store) can make doing the deed safer and sexier.

Additional reporting by Markham Heid