At school in the 70s it was vital, for the purpose of not getting your face bashed in behind the bike sheds, that your parents had, a) a good car, b) a house in the proper part of town, and c) jobs from the approved list. I was down on points for all three.
Our vehicle was a rusty Renault 4 van, which attracted attention to itself with loud whining and farting noises when I was dropped off in the morning, our small house was on the cusp of nowhere and my parents' jobs were an unspeakable embarrassment. My father, who had once been a Dominican friar, was now a schoolmaster – dangerous enough. But my mother was, God help me, a sex therapist.
The 70s were a time before therapy became the must-have fashion accessory it is today, and if this mystical-sounding profession had been heard of by my desk-slamming peers – which it hadn't – it would not have been granted their imprimatur.
Indeed, when we had to write down our parents' occupations in Mr Price's civics lesson, I omitted the radioactive word "sex" from my mum's job title out of an instinct for self-preservation. It did me no good because Bob McGrotty shouted out from behind me, "Oi! Cutler's mum's the rapist. Cutler's mum's the rapist."
I knew from experience that playground associates were also capable of acts of hideous betrayal. When poor little Tony Smith whispered to some smiler with the knife that he fancied Denise Pumphrey, he found his indiscretion sprayed in two-foot high green capitals all over the remedial hut next morning. So I was guarded about exactly what I told exactly whom.
Close friends were a different matter. If they asked what my mum did for a living, I told them. Liking to regard themselves as sophisticated boys of the world, they thought it all rather exciting. Mild discombobulation was occasionally voiced about the question of just how my dad, who in his former vocation had taken a vow of chastity, had ended up with a wife who listened all day to people talking about their penises. But as my amiable mother administered smiles and cucumber sandwiches, my school chums noted that she appeared not at all sex therapist-like but quite ordinary and found themselves able to make allowances for her daytime calling.
I wondered, though, what I ought to tell girlfriends. Fired up with youthful carnality in the early days of a romantic relationship, it seemed vital to appear assured, witty and sophisticated, rather than merely lust-crazed. Would telling a girl, "My mum's a sex therapist" add to my seductive allure or just make me sound like the callow and boastful offspring of a species of female sex-creep? I bit the bullet and announced to Evelina what it was that my mother did at the office. She took it in her stride like the classy girl she was and things went swimmingly thereafter. For a bit anyway. In the end the unbeatable glamour of Ray Melly's red Triumph sucked her clear of my ambit.
A handful of sweethearts down the line, the girl who became my wife never batted an eye when she learned what my mother did and we have been happily married for donkey's years, with hardly a saucer thrown. By the way, and for the record, I have never sought, nor needed to seek, any technical advice from my mum. Apart from the usual motherly stuff about the proper way to treat a girlfriend, she has never offered me guidance, practical, emotional or otherwise about her area of expertise, and for this I remain grateful.
While my wife didn't care what my mother did to earn a crust, it was a different story with my father-in-law. When he learned that his daughter was to marry the son of a sex therapist, he showed his displeasure by having a heart attack. Not then and there: he saved it up for the evening before our wedding, for maximum effect. He pulled through in the end, seeming to accommodate himself to the idea of me – and my mum – as time went by.
My mother was always professionally discreet and spoke to me about her work only in the vaguest generalities. I recall that she did once describe something called restless genital syndrome, a condition that causes spontaneous, uncontrollable and persistent genital arousal, unconnected to any feelings of sexual desire.
This arousal can be intense and, though orgasm may provide relief, the symptoms are wont to return suddenly, unpredictably and with a vengeance. In women, this causes wave after wave of spontaneous orgasms to erupt just as they are doing a bit of shopping. In men, it can result in impromptu ejaculation at the bar, petrol pump or job interview. Bus and train rides become not only inconvenient but also hazardous, as vibrations aggravate the syndrome.
But, apart from the occasional description of odd sexual maladies, I was never privy to the specifics of the people involved in my mother's therapy sessions. I know that the commonest sex problem she encountered was impotence – what is today politely called erectile dysfunction, or, rudely, ascension deficit disorder. But this, she maintained, was almost always more to do with the couple's relationship than with the gentleman's plumbing. Apart from clear medical causes, such as very poor cardiovascular health or longstanding diabetes, sex problems were likely to arise, she said, between the ears rather than between the legs.
In the 80s, my parents moved to Berkshire, where my mother went into private practice on her own. When I once asked about the kind of guidance she gave her customers, she explained that she almost never did, preferring instead to allow them to talk about what was bothering them.
In therapy it often became clear that couples spoke little to each other in daily life, not only about sex but about anything, and, in extreme cases, communicated exclusively through terse notes taped to the fridge or pinned to the shed door. Men failed to understand what women wanted and women failed to tell them, and vice versa. So, she would sit in her consulting rooms, gently nudging ordinarily non-speaking life partners this way and that, while they unravelled the long threads of their distress by just talking and listening, sometimes for the first time. In most cases, said my mum, this was like unstopping a bottle of tribulation; and helping her clients to let it all out commonly proved a solution to the physical problem.
Of course, the talking cure was not her idea. Freud had begun doing it at the end of the previous century and by the 1970s varying flavours of psychotherapy had become popular around the globe.
The world-renowned sex researchers William Masters and Virginia Johnson, who claimed to have observed more than 10,000 orgasms in the course of their studies in the late 1950s, 60s and 70s, had developed methods for treating premature ejaculation, impotence and female frigidity (now called hypoactive sexual desire disorder), using two-week talking sessions. They claimed a success rate of about 80%, which sounds almost unbelievably high. Though my mother had fewer clients, she tended to spend longer with them.
Working from consulting rooms under the thatch of her village home beside the river, she would begin her days, like anyone, with a bit of breakfast. The first caller might arrive at 9am and she would then be opening and closing the door all day to people with problems of every stripe. By this time, my siblings and I had left home and only my father remained.
Being a retired gentleman with elbow patches and a tired look, he would make himself scarce, retreating into the kitchen or study, or going to the London Library on the grounds that he had to return a book, possibly on the subject of metaphor or international jurisprudence. He still does this whenever my mother is conducting a couple of days of sex therapy with people, which she still occasionally does, even though she is now in her 80s. I guess her rheumy eyes are today taken by premature ejaculators and the frigid alike as a sign of sagacity, which they may well be.
Since her "official" retirement, my mum has earned enough at the therapy racket to fund world cruises aplenty, though on the boat she is liable to keep quiet about her profession for fear that the other old dears will all request advice over their poached sole.
Her straightforwardness on the topics of sex and what can go wrong with the sexual psyche led me as a boy to view the subject first as intellectually interesting and, second, as perfectly normal, in all its incredible variety. As a consequence, my own son has been brought up in an unembarrassed household where sex questions have always been answered in plain words, and often with a laugh, for if sex is not a funny subject then what is?
Whether it was my mother's odd job that led to my becoming a writer for whom sexology is a big theme, I can't say. But my own attitude to sex is this: I'm all for it.
Tom Cutler's book Slap & Tickle: The Unusual History of Sex and the People who Do It is published by Constable at £12.99. To order a copy for £9.74, including free UK p&P, go to theguardian.com/bookshop or call 0330 333 6846
