Lipstick and bonking, that’s what it’s all about when a recession hits. Or so they say. Because when I think of myself (or most of my friends who have been in relationships for 13 years or more and have kids), I can assure you that’s not how it is at all. Oh, sure, we can tell you all about Youporn.com, and only the other evening I went to a dinner where one of the guests had bought, as an amusing gift for our host, a jar of fisting lubricant. The more unshockable we appear to each other, the better. But when it comes to actually doing it? With each other, I mean? After one’s other half has been up the sharp end for a couple of births and seen a few piles? Ewww. That’s for German naturists and kinky folk in the suburbs, is it not? But time is running out. I have to accept the fact that I’m never going to get to do it with Nicholas Hoult (the boy from the old series of Skins). I have to accept that, if it carries on much longer like this, everything might close up. Sex is natural; after all, it’s part of life, like tilling the soil. And so off I go on a mission to find that oh-so-rare species, the couple who have been together for ages, are all kidded up and still have absolutely filthy, chandelier-swinging sex. First up is Charlotte, 40, and her entrepreneur husband, Damian, 43, who have been together for 14 years, have two little boys, and have sex, gulp, five times a week. “At least five times,” giggles Charlotte from their west London home. “I swear he’d do it five times a day if he could. He would have jumped me in the maternity ward if the doctor hadn’t been there.

“Regular, frequent sex keeps our relationship healthy and balanced,” she adds. “He gets all antsy if he is deprived, so even if I don’t particularly feel like it or I have my period, I always acquiesce. But don’t think it’s three-hour marathons every time. More often than not, it’s cosy 30-minute quickies in the morning, before I get up for the school run. And if one of the boys walks in, well, Daddy’s doing his exercises, isn’t he?”

Regularity. That’s the key. Maybe getting a little trashed is, too. Take Susie, 45, and Rob, 48, a record producer from Oxfordshire, who have been happily married for a decade and have six-year-old twins. Every Friday night it is the same. They get in two bottles of Cristal, put a sofa up against the living-room door, get out Susie’s little dressing-up box (last week she wore her catsuit) and then go at each other like stink.

“It’s hard when you have young kids, there’s no doubt about it,” admits Susie, a former luxury-goods PR, “but if you ban men from watching porn by themselves, which, in the fullness of time, makes them harder to get turned on by the real thing, and never get too familiar in the first place, yes, you can preserve some of the magic. I can’t believe I’m telling you this, but I have never once heard my husband fart.”

Aha, breaking the sound barrier in front of each other. So that’s where we’ve been going wrong. So, tell me, is it possible, once you’ve turned your lover into your brother, to turn him back into your lover again? “Quite possible,” promises Kathy, 38, a former actress married to a wealthy businessman 12 years her senior. “On a sexual scale of zero to 10, I can tell you, we were both at zero after I had our third child three years ago. The idea of sleep was so much more exciting than sex. But, by consciously reinventing ourselves, reintroducing an element of risk into our sex life, it has zoomed back up to 10. For example, we went to dinner the other night and snuck to the disabled loo for a quickie. We also go to saucy clubs, where I make out in front of him with other girls. That’s a huge turn-on for him, and, by proxy, for me. None of our friends, or, indeed, any of the mothers on the school run, have any idea that we have a parallel life. We are very conventional, conservative people. I suppose the risk of getting caught is what makes it so exciting.”

Right, then. Onwards and upwards. Just for tonight, though, would it be okay if I just read my book?

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