Single women over 50 are much more likely to have a one night stand than their Gen X daughters - or even their Gen Y daughters - according to new research from Nielsen, commissioned by dating site RSVP (which is owned by Fairfax Media.)

And during those one night stands, those older women are much less likely to have protected sex.

That research is straight from RSVP's Date of the Nation, which surveyed 3300 Australians earlier this year and found that across all age groups, two to four dates is the average number of meetings before getting it on. And Australian singles over 50 are the most likely group - of any - to have sex on the first date.

General manager of RSVP, Glenis Carroll, says that just over 20 per cent of singles aged over 51 will have sex on the first date, compared to 14 per cent of singles who are Gen X or Gen Y.

"They are at a different stage in their lives - they are not looking for The One. They still think a serious relationship is important but more than two-thirds say they are happy being single," she says.

I've even got the friends to prove it. One old mate, now a senior public servant who absolutely forbade me to use her name, says she'd been single for a little while and woke up one morning absolutely desperate for sex.

She reactivated her profile on RSVP and within an hour had made contact. They had dinner and a shag that night.

"It was definitely unsafe sex," she says. Sounds like she's remembering it fondly but reminds me she's been very happily with the same bloke for three years now. And plans to keep it that way.

Gail Wilkie, 49, of Ballina, who responded to my callout on Twitter last night for older women who'd had one night stands, says her last experience like that was when she was 44.

"I'd just broken up with a fellow and a friend of a friend had set me up so I'd get over it.

"It was just one of those spur of the moment kind of things and I've always been a risk taker," she says.

It too was unprotected sex (although she was on the pill), which Wilkie admits is amusing since she has always preached safe sex to her three children.

"We've always had condoms in the cupboard - but this is more of a case of 'do as I say, not as I do."

Wilkie says: "When my generation was young, it was pre-AIDS so condoms never really became a habit or are something we are used to."

And these are precisely the women Deborah Bateson, the medical director of Family Planning NSW, is targeting.

Her survey, conducted in 2009, confirms women over 40 were more likely to agree to sex without a condom.

And the latest figures from the National Notifiable Diseases Surveillance System show that since 2005, the number of new cases of chlamydia in people aged 40 and older has doubled. Bateson says that gonorrhea too has increased in the over 40s

Why don't women in their 40s and 50s practise safe sex?

Bateson says it may have to do with not being part of the condom generation, there is a lack of awareness, may find it difficult to raise the subject with their GPs and there has been, so far, no campaign targeted at older people.

Linda Kirkman, a PhD candidate at Latrobe University's Rural Health School, is conducting research on rural babyboomers in "friends-with-benefits" relationships. She has defined that as friends with ongoing sexual relationships but who do not consider themselves to be a couple.

She's interviewed 19 individuals who have a range of relationship configurations, from serial monogamy through to polyamory (many lovers, respectful consensual non-monogamy).

A sexuality educator and researcher, she has found different approaches to safe sex, including people who feel they know a prospective partner well enough to make a decision about whether they are likely to have an infection.

She has also interviewed those who are very strict about safe sex - and those who know all the theory and all the rules but would rather take the risk of a sexually transmissible infection than risk rejection by insisting on condom use.

Like Bateson, Kirkman says most safe sex campaigns are pitched at the under 30s and they have a focus on protecting reproductive health.

That changes today. Family Planning NSW today launches its Little Black Dress campaign to raise awareness about safe sex for older women embarking on new relationships later in life, with a short video clip guided by 76 women who took part in the original survey back in 2009.

As they say, it's an easier conversation to have with your clothes on but it just may take more than one night to sort it out.