The Centers for Disease Control and Prevention has a message for sexually active Americans: 'Don't wash or reuse condoms,' the agency tweeted this week.

Most Americans (72 percent) are having sex, and about one in every four are using condoms - but, apparently, we aren't all doing it right.

'We say it, because people do it,' the CDC said.

In fact, research has found that as many as three percent of people have tried to reuse condoms, and half us have put a condom on too late or removed it too soon.

Condoms effectively reduce the risks of contracting sexually transmitted infection sand help prevent pregnancy, but only if used correctly.

So the CDC is here to remind us all that the prophylactics - which can be purchased for 50 cents or picked up for free at many health centers - are one time use only.

The CDC tweeted a warning this week that condoms are ineffective after one use, urging Americans to splash out for a new 50 cent (or free, at health centers) condom each time

Humans have had nearly 200 years of practice using condoms since they were but we still mess it up with surprising frequency and in scores of novel ways.

Even the most obvious errors, like washing or reusing condoms, are horrifyingly common.

In fact, between one and 3.3 percent of people people try to reuse them, according to one meta-analysis published in 2012.

In all fairness, sexual education in the US is infamously a target of criticism by sexual health experts.

And, as simple as they look, there is only one way to use condoms correctly, and so many more ways for things to go terribly wrong.

According to the same study, the most common mistakes people make when using a condom are putting in on too late (as many as 50 percent of respondents) or taking it off too soon (up to 44.7 percent).

But you could also undermine the prophylactics' effectiveness by doing things like unrolling it before putting it on (instead of unrolling it onto the penis) or partially unrolling it, not leaving space at the tip for semen collection and failing to use lubrication.

Early condoms like this Durex actually came with instructions to wash them. They also had a seam the side and were made of actual rubber. We know better now

Anything that damages a condom - like storing it in the wrong conditions, any contact with sharp object or fingernail or even oils from lipstick - can render it ineffective.

After one use, a condom has been unrolled, and the friction of sex weakens the rubber.

Most importantly, they are no longer sterile after use. After using a condom once, it has already come into contact with bodily fluids.

And soap is no help.

Viruses, bacteria and semen are all too tiny for washing to be a guaranteed way to remove them.

To be fair to the one to three percent of people who have tried to wash away STI risks and reuse their rubbers, this is actually a relatively recent development in our understanding of sexual health and safety.

The first rubber condoms - invented in 1839 - were thick, had a seam down the side and came with instructions for washing them in a box the size and shape of a jewelry gift box.

Rock stars like the Sex Pistols and Elvis Costellos even sang about washing their condoms, as recently as the 1970s.

Now, science knows better, and most of us do, too.

But, just in case, the CDC is here to remind us all that condoms are one-and-done, and only work when you use them correctly, every time, the whole time you engage in sex.