I began to suspect that my wife, Isabel, was up to no good about six months ago. We have been married for seven years, and although there is nothing routine and boring about our marriage – we would both describe our marriage as happy – she got into the habit, after about three years, of jogging every Saturday and Sunday morning (unless we went out for the day or were on holiday), and most Thursday evenings when I worked late.

She would also go jogging sometimes if I went out for a drink with my friends from work. Normally, the business of getting ready, warming up, jogging through the park to the nature reserve and back, doing further exercises at home, and then getting undressed and having a shower took about two hours, which I always felt was a little too long and sometimes complained about.

However, one Sunday morning six months ago, she took longer than usual, by about half an hour at least; she told me that part of her usual route had been fenced off due to some land reclamation work going on. The following Saturday, it took her an hour longer, and she said that even more land had been barricaded off. It looked as if this work would go on for some time.

I suggested she change or curtail her route, but she said there was no alternative – the other parks were too far away, and the terrain over other parts of the nature reserve was too rough and almost impassable. I would just have to get used to the idea that for some weeks, she would be home an hour later than usual from jogging.

Some Saturdays and Sundays, she was delayed by more than an hour, and sometimes when I came home from working late on Thursdays, she would not yet be there; she would turn up half an hour later, hot, sweaty, and flushed, and take a quick shower.

Then, one weekend about three weeks after her extended jogging sessions began, she asked me whether I planned to go out for a drink the following week. Normally I didn’t make such plans until Monday or Tuesday, and would not go out until Wednesday evening at the earliest. I seldom went out more than once a week, although sometimes after working late on Thursday I would have a few drinks in a bar nearby with my colleagues.

I said I might have a drink with John or Peter or Len, but as yet had made no plans. She asked me to let her know as soon as possible, because she would then arrange to leave work early that night so she would get home earlier and have time to go jogging before it got dark. I nearly fell off my chair. She couldn’t possibly want to jog any more than she was already? It was already taking her three hours a week more than usual. But she was insistent: she wanted to jog more often, as she didn’t feel as if she was fit enough.

From then onwards she asked me regularly, every weekend, whether I had planned to go out for a drink next week. She even began to suggest that I go out with old so-and-so who I hadn’t seen for some time and to encourage me to meet up with friends of mine whom she had once claimed to dislike. Before long I found myself going out Tuesdays and Wednesdays, working late Thursdays and going out again on Fridays. It was pretty exhausting, to say the least.

But not so exhausting that I failed to discern certain changes in my wife. Firstly, she seemed much more happy and vigorous than previously. Like many career women, privately she often felt inadequate – she wasn’t pretty enough, she was too fat, she didn’t have enough clothes to wear, her career was a failure; none of which was true, of course, but she always ran through this litany at least once a week.

Now she never mentioned her feelings of inadequacy at all. She was cheerful – dare I say sunny – all the time. Secondly, she started to dress the way she had when we first got to know each other. All the clothes she had mothballed in the past few years because she was older now and didn’t want to “look like mutton dressed as a lamb.”

She shook out and started to wear again: crisp white blouses; tight T-shirts that enhanced her bust-size; low-cut tops; her denim mini-skirt and denim mini-dress; her black, red, and yellow leather min-skirts; her tartan pleated mini-skirts (she had them in red, green, and yellow); her two short black dresses, one flared, the other figure-hugging; her denim, black leather, red leather, and yellow leather hot-pants; her stockings and suspenders; her fishnet hold-ups; her shiny black, white, red, and imitation snakeskin mackintoshes.

She sorted out her collection of footwear, asking me to polish this or that pair of cowboy boots, riding boots, lace-up boots, over-the-knee boots, or thigh-boots. Now, when she went to work in the mornings, instead of wearing a trouser suit with boots underneath, she wore stockings or hold-ups, a skirt or dress (always above knee length or shorter), and either cowboy boots or knee-high boots. Occasionally, she wore thigh-boots but with the flap folded down. (She had five pairs, but only two of them were low-heeled and suitable for work; the others were strictly for the bedroom!)

Thirdly, she began taking more interest in her appearance. At first, she just started polishing her nails more often, then she began to apply nail varnish, then to experiment with make-up – a little lipstick here, but a bit of eye-shadow there, perhaps some foundation, some eye-liner, and mascara – until she was satisfied she had attained a certain “look”.

Then she had some more piercing done. She already had one ring in each earlobe and another at the top of her right ear; but now she had in addition two studs in each earlobe, another ring at the top of the right ear, a new one at the top of the left, a stud through her right eyebrow, and two studs (which she later replaced with rings) in her right nostril. In the following months, she would have further piercing done, but more of that later.