Baby-making gave me an inflamed groin and exhaustion '“ Steve Canavan

The reason is that she has downloaded on her phone an app (older readers should consult their grandchildren) that actually works out when she is most fertile (apologies if you're midway through a sandwich) and tells us exactly when we should be, well, you know, getting down to business.

Now in the old days, when Mrs C and I first met and we actually had feelings for each other, we would get down to business fairly regularly and it was always moderately enjoyable, mainly because we did it when we liked. It was off-the-cuff, spontaneous.

But being instructed by a mobile phone when to do it is, I have to say, an incredibly depressing state of affairs.

The other night I was halfway through a Channel 4 documentary about a gentleman from Doncaster who lost his legs in a yachting accident when Mrs C appeared at the doorway, gave me a sympathetic nod of the head, and said, '˜it's time'.

I was slightly drowsy after a long day at work and was initially confused as to what she was referring to.

'˜Time for what?' I replied, puzzled.

'˜You know,' she said, '˜to go upstairs and try'.

For a moment I thought she was talking about the grouting in the bathroom '“ she's been on at me to sort it for weeks because we've quite bad mildew between the tiles nearest the showerhead '“ but then I realised, with horror, what she really meant.

'Oh god, do we have to?' I blurted, which I'm pretty sure wasn't my response the first time Mrs Canavan invited me to the bedroom a decade or so ago.

'˜I'm afraid so,' she said, slowly, with all the solemnness of a vet informing you he's got no other option than to put down your beloved 15-year-old Cocker Spaniel.

I sighed heavily.

'˜Look,' she said, '˜I don't want to do this either. In fact there's nothing I'd rather do less. I've got a headache and my athlete's foot has flared up again, but we need to do it. So let's just go and get it over and done with.'

As arousing speeches go, it was on a par with Hitler at Nuremburg.

So we climbed the stairs, went into back bedroom (we didn't use our main bedroom as we'd just changed the sheets; I'm at an age where there's no way I'm going to risk a newly washed duvet cover getting dirty) and half-heartedly '“ perhaps maybe even quarter-heartedly - went through the motions. Midway through I noticed Mrs Canavan had stopped moving and I glanced up to find her sending a text message on her phone. '˜Sorry,' she said, noticing me staring at her, '˜I forgot to ring the electrician about that plug socket in the lounge'.

It was less Lady Chatterley's Lover, more Nightmare on Elm Street.

We carried on till the bitter end, deriving no enjoyment from it whatsoever (Her: '˜are you done yet?' Me: 'I'm trying, give me a couple more minutes') and then, deed done, Mrs Canavan rolled on to her back and '“ because she's read this is the best way to ensure the bits needed to create a baby actually get to the right place '“ put both legs vertically in the air, as if she were practicing some sort of X-rated circus trick.

And this, dear reader, is just one example.

Over the past four weeks I have had to do this kind of thing twice a day, sometimes over the course of a full week. I've got a terribly inflamed left groin and I am so tired I now fall asleep during The One Show '“ though I'm often woken by Mrs C if her app makes a peeping sound and tells her it's a good time.

On the off-chance you're trying for a baby and want to suffer in the same way I am, there are loads of these baby-making apps to choose from.

Take one by the name of Fertility Friend for example. It's free, but for $45 you get advanced features like '“ and I'm not making this up '“ '˜an intercourse timing analyser' (me neither) and VIP access to message boards ('˜we did it loads the other week but I'm still not preggers #gutted. Janet from Portsmouth).

There's another called Kindara, which monitors cervical fluid; Conceivable, which involves taking three herbal formulas that '˜remove specific obstacles to your natural fertility'; and another called Tinder, in which you can get a bloke to come round to your house and have a crack himself.

It's all very depressingly modern and makes you wonder how anyone ever got pregnant in days gone by.

I'd write more but I'm tired, my groin hurts, and I need a lie down, so till next week'¦