It's one of those questions that could drive competitive types nuts: how long does the average couple spend having sex, anyway? And, more importantly, do you last longer than your partner's previous lovers?
Happily, Dr Brendan Zietsch of the University of Queensland has the answer - sort of.
"The average time for each couple (that is, averaged across all the times they had sex) ranged from 33 seconds to 44 minutes. That's an 80-fold difference," writes Zietsch writes for The Conversation.
Given the time-bending properties of an excellent session in the sack - and, of course, that people are more inclined to skew toward the longer side when asked to self-report on this kind of data - figuring this out in a scientific way was awkward, to say the least.
Couples had sex using a stopwatch
To forestall against error, researchers asked 500 couples to time themselves having sex over a four-week period using a stopwatch. Understandably, that kind of pressure could interrupt the natural progression of things - but, as Zietsch points out, "science is rarely perfect, and this is the best we've got."
"The average (median, technically) across all couples, though, was 5.4 minutes. This means that if you line up the 500 couples from shortest sex to longest sex, the middle couple goes for an average of 5.4 minutes each time they do it."
Weirdly, condom use didn't seem to affect the time, nor did whether a man was circumcised or not - two secondary findings that challenge the accepted wisdom about the link between penile sensitivity and staying power.
Nationality didn't seem to factor in the average lovemaking time, either - unless respondents were from Turkey, where respondents reported their average session lasted only 3.7 minutes - significantly shorter than couples from the Netherlands, Spain, the United Kingdom, and the United States. Another surprising finding? The older the couple, the shorter the sex they seemed to have.
So, you can officially chill out: it seems the amount of time you're having sex is totally normal and fine - provided, of course, that both of you go to sleep satisfied.