The next time you hold a dinner party for 12, try and figure out which of those couples might not be having sex, or allowing themselves to see each other naked.
Actually, on second thoughts - don't - that would be beyond creepy. However, two new studies have shed light on some rather disconcerting facts about married life.
Specifically, married sex life.
The studies are both fairly small, so it may all be utter tosh. But - having done a straw poll - there are a surprising number of married couples for whom sex has sort of fallen off the radar.
In one study by We Vibe, 15% of married couples said they didn't have sex anymore (by that, they mean regular, weekly sex), while another by UKMedix.co.uk said that 1 in 6 women won't let their husbands see them without clothes on.
The latter survey revealed that all respondents who claimed that they hadn’t allowed their partner to see them naked in 12 months or more were asked why this was the case.
The majority, 45%, explained that their ‘lack of body confidence’ had caused them to hide their body away from their partner, while just under a third, 30%, also explained that their ‘libido was lacking’; and therefore they hadn’t felt the need for their partner to see them in the nude.
Sex expert Tracey Cox says that the longer you go without sexual contact, the harder it is to break the cycle. "It’s also true that the longer you go without sex, the less you miss it. This is why it’s imperative that you both don’t adopt the ‘head in sand’ approach when sex does decline. Tackle it head on. It’s important for long-term happiness."
However, it's important not to start worrying about what's 'normal' and whether you need to compete with your peers. Having less sex when you're married is perfectly ordinary, the experts say.
"Couples have sex with each other less often the longer they are married," adds Tracey. "Married adults under 30-years-old say they have sex an average of 109 times a year. The average drops to 70 times per year for 40-somethings and 52 times a year for people in their 50s."
In any case, says The Times sex expert and columnist Suzi Godson, with regards to couples not having sex, we need to take statistics from a sex toy company with a "pinch of salt".
"Sexlessness has become a bit of a bandwagon but the fact that sexual frequency declines with the duration of the relationship does not necessarily mean that couples are dissatisfied. Quantity has never equated to quality and if you and your partner are perfectly happy having sex once a month then you do NOT have a problem.
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"Sex is a really important part of our relationships because it makes us feel happy and connected, but it's not a competitive sport and there is a lot of unnecessary anxiety around sex, or the lack of it, in long term relationships."
However, there is a distinction between not having sex at all and reducing the amount you have sex.
Sex therapist Mike Lousada says: "Typically if a couple is not having sex its because something is being ignored or suppressed in the relationship. My best tip for re-kindling desire is to be honest with one another. Sex is usually great in the honeymoon period because we use our best moves - and since we (and those moves) are probably new to our partner, they feel very exciting.
"However once these intense "honeymoon" feelings subside, something more emerges - which are often uncomfortable feelings or stories - I'm not good enough, he/she is bored of this, I'm bored of this, etc. Such emotions tend to make us feel uncomfortable. Rather than share these uncomfortable feelings we try to hide them or avoid behaviours (like sex) that illicit them. So sex gradually becomes less and less comfortable and more and more limiting."
What's the solution? Mike adds that the best way to start up desire again is to be compassionately honest with one another.
"Speak from your heart, remembering that your partner also has their own emotions and vulnerabilities. Stick to talking about your own experience and how you feel."
It also requires both of wanting it to work. "It amounts to two people making a conscious decision to try and have more sex and to make the sex they have more entertaining," says Suzi.
More controversially, Tracey suggests having sex even if your first reaction is: "I don't feel like it".
"Men are more likely to follow the original model and feel ‘spontaneous’ desire – the ‘want it, then seek it’ variety – while women’s desire is ‘receptive’ – they get turned on by being physically turned on," she advises.
"This might not sound terribly exciting or significant, but for low or no desire women (and some men – this model isn’t completely gender exclusive), it’s the sexual equivalent of inventing the wheel. It means you’re not boring, ‘frigid’ or cold after all - you simply get turned on in a different way! Start to have sex, even if you don’t feel like it, and see what happens. You might well find you get turned on, along the way."