But that Sunday evening, her husband sheepishly confessed that there had been a mystery ingredient in their lovemaking: Viagra. "He'd gone to Boots pharmacy during the week, bought a packet of Viagra Connect and taken one on Friday evening," says Sian, whose husband is nine years older than she is and has a stressful job in finance.
"All Tony would say was that he's 'tired' these days and wanted to see what it was like. He was quite casual about it but I didn't feel casual at all. I felt stupid for not realising at the time; it made the sex feel deceitful, a bit humiliating. If he'd been having a problem, why didn't he tell me instead of going out and buying some pills? Does he need one from now on to feel turned on by me? He thought I was overreacting, and said 'half the world' is taking Viagra. By Monday, all that good feeling had gone and we were sleeping back to back."
Though Sian's husband is pushing it when he claims that"'half the world" is taking it, Viagra is certainly transforming sex and relationships. When it arrived in the UK 20 years ago, "impotence" was not so much a "medical condition", as an "inconvenience" or a sad fact of life. Now it's known as "erectile dysfunction" and by no means limited to older men with underlying health conditions, such as prostate cancer or Parkinson's disease.
Viagra users might include a teenager worried he won't last long enough with his girlfriend; a 20-year-old who's hooked up with a girl on dating app Tinder and worries she expects a porn-star performance between the sheets; a middle-aged married man whose sex life is flagging because his erections aren't as firm or long-lasting as they were in his prime. For anyone feeling "let down" by a past performance, Viagra promises to turbocharge lovemaking without embarrassment, effort or awkward conversations.
Viagra (like the many other erectile dysfunction drugs that have flooded the market such as Cialis and Levitra) works by increasing blood flow to the penis, enabling a harder, longer-lasting erection. Its effect varies according to the metabolism of the man who is taking it and other factors. There are documented cases where one pill has produced an agonising ten-hour erection which just doesn't go down but, in general, the effect of Viagra wears off within two to three hours of taking it.
But what about the women whose partners are buying those little blue pills? How has Viagra altered sex and relationships for them? There have been a number of well-publicised "Viagra divorces" and several lawyers have claimed that the drug is causing men to stray by facilitating late-life sexual adventures. Divorces where Viagra played a part include those of comedian Vic Reeves, DJ Ed Stewart, pioneering heart surgeon Christiaan Barnard and Johnny Kidd – father of Jemma and Jodie. In the past a suspicious wife might check her husband's pocket for hotel receipts, but now she is just as likely to count his Viagra supply.
Earlier this year, 71-year-old Diane von Furstenberg, designer of the iconic wrap dress, said Viagra was the "worst thing to happen to women". Where once age lowered libido or slowed sex down for both sides, Viagra has helped men hold back the years. "For men it used to be all about getting it up. 'Can I?' There was a certain fairness." Just as the contraceptive pill freed women to enjoy sex without the normal biological consequences back in the 1960s, Viagra has freed men to enjoy sex without the normal biological ageing process to hold them back.
Aside from the heightened threat of infidelity, Viagra is bringing female partners pressure as well as pleasure (three-hour sex, anyone?). It's raising tricky new questions (does he still fancy me or is this the drug talking?) and whole new layers of negotiation (what's the etiquette here: should he always ask before he takes one?).
The Viagra revolution
Psychotherapist Christine Webber was an early witness to the Viagra revolution as her late husband, doctor and media sex guru Dr David Delvin, was one of the first to prescribe it in the UK back in 1998, before it became available on the NHS. "There weren't enough hours in the day; we had men queuing round the block of our home in Cambridge, where David's private consulting room was based," she says.
"Patients included young men who couldn't achieve erections and wanted to impregnate their wives, men in their 80s – one was a university don, another a vicar. When they arrived, they were embarrassed, eyes cast down. The next time they came for a repeat prescription, they looked 20 years younger and were standing taller: they looked you in the eye. I've never forgotten the transformation. Getting their favourite part working efficiently was like birthday and Christmas rolled into one."
Whether it was quite so joyous for their wives is impossible to know. But Gillian, now 78 and a widow, whose husband took Viagra when they were in their 60s, sounds a cautionary note. Vibrant, open and no prude, she was nevertheless quite content to have put their sex life "to bed" until that point. "It had been two years – and not very often for years before that – so you can imagine the physical impact on me of starting up again," she says.
Though the loud and clear message these days is that 60 is the new 40 (and with 60-year-old Madonna a role model in bodice and boots), for many menopausal women penetrative sex, even with lubrication, is painful. As levels of testosterone, progesterone and oestrogen all drop off, skin becomes drier and thinner. A suddenly revved-up sex life – especially longer-lasting Viagra sex – can cause pain and abrasion, even "honeymoon cystitis".
"I'd got to the stage in life where I'd rather read a book," says Gillian.
"Then suddenly, sex is back on again, and it's his new hobby, his preoccupation. You don't want a row, so what do you do? He'd start cuddling and I'd ask warily, 'Have you taken one of your pills?' He'd get all cross and say, 'Yes – I don't need to ask permission to take a pill!' Then you'd have this pressure not to waste it."
Overall, Gillian has mixed feelings about the drug. On the one hand, it made her husband happier in his last decade and it did bring them more shared, intimate moments. On the other, intercourse wasn't something she enjoyed any more. At times, it felt as though his favourite thing had become her private dread and that gulf between them sometimes made their marriage feel lonely.
Women's online spaces such as Mumsnet show that Viagra is often an emotional minefield. In one thread, a woman is "shocked" and "struggling" after discovering her partner has been taking it for two years without telling her. "He says that using it means he can perform for longer and he chooses to use it because he wants to make sex fantastic for us both," she writes. "I feel that what I thought was real wasn't after all. What else isn't he telling me?"
A Viagra prescription ended my marriage
For relationship coach Cathy Meyer, a Viagra prescription signalled the end of her marriage. She spent 11 years struggling in a sexless marriage – her husband told her that he just didn't see what the "big deal" was about sex. Cathy tried every seduction technique and when nothing interested him, she finally persuaded him to see a urologist to see if there was any physical reason behind his lack of desire.
"I was sitting in bed reading when I heard him coming up the stairs. He stopped by our bed, pulled a bottle of pills out of his pocket, opened the top drawer of my bedside table and said to me, 'This is a bottle of Viagra; from now on when you want sex, all you have to do is ask for it.' He dropped the bottle in the drawer and kicked it closed with his foot. I knew at that moment that my marriage was over," writes Cathy in her divorce blog. Though her husband had been given the physical "solution", he was not emotionally invested, not sensitive to her needs.
Clearly, Viagra isn't a miracle cure – it deals with mechanics not emotions. "It works on a symptom and it works very well, but it doesn't solve a troubled relationship or create a desire that isn't there," says therapist Christine Webber. Since it takes an hour to kick in, it also requires planning. And psychotherapist Simon Jacobs feels strongly that taking it should be a joint decision. "It's not a man's right to take a pill, have an erection and be able to use it," he says. "It's important that you take it as a couple, not unilaterally and certainly not in secret."
He also counsels against taking Viagra without first exploring other possible reasons behind erectile dysfunction. "If a man is worried by his performance, especially a younger man with no underlying health problems, there's likely to be some strong psychological reasons behind this," he says. "It could be stress, relationship problems, unexpressed resentment or just the belief that you need to be a porn star in bed.
"Popping a pill and getting an instant erection means you don't need to look into any of that so it can be quite dangerous, especially if you don't confide in your partner," Jacobs continues. "Then the man is living with his problems alone; he has added a secret which piles on more anxiety and leads to more performance problems. It makes it worse.
At times it felt as though his favourite thing had become her private dread and that gulf sometimes made their marriage feel lonely.
"Most women don't expect their partners to perform seamlessly, with no hiccups, no embarrassing moments," he continues. "They want a real human being, who isn't afraid to share real vulnerabilities. If you have a sexual problem and work it through, whether by talking openly to each other, having sexual therapy or taking a pill as well, the relationship strengthens and self-esteem strengthens because you've faced it together and come out the other side. Secrecy just isn't going to help."
Viagra doesn't create desire
Women shouldn't feel any less desirable if Viagra is needed, adds Sarah Fletcher, psychosexual therapist at Coupleworks. "Viagra doesn't create desire," she says. (If a man suffering from erectile dysfunction pops a pill then watches the golf on TV, it's probably not going to work. He still needs to be turned on to get a rise.)
"Your husband may still find you attractive, but that may not produce an erection. Viagra can help with that. People drink and have sex all the time – that loosening of inhibition is chemically enhanced, too."
When it comes to men being led to stray by Viagra, Fletcher isn't convinced. "I think it's a bit more complicated than that," she says. "If a man is going to be unfaithful, it would probably have happened anyway – or I'd certainly say there are other problems in the relationship. I think, overall, Viagra has been a positive thing for couples."
Saviour or destroyer?
One survey by Oprah magazine targeted women whose partners had taken Viagra to see whether it had been a good or bad thing for their relationship. The results were interesting. While 15 per cent claimed the drug wrecked their relationship, 17 per cent said it had saved theirs. Though 13 per cent lamented the reduced attention given to oral and manual lovemaking, about half of all respondents said it made sex better.
Lucy, 37, is firmly in the latter camp. "My husband and I have been together a long time, we have children, we're knackered and sometimes we had some problems with keeping things going," she says. "It bothered both of us, but for my husband, it was crushing. Viagra was fantastic – it showed him that there was this solution, so it took the pressure off. We don't always need it and I certainly don't fancy it on a school night – but maybe once a month, we'll plan ahead and skip dinner [Viagra works better on an empty stomach]. It's made us both happier, and I'm very grateful for it."