He felt a rush of desire for his wife of 10 years, and all it took was this.

The yearning I felt at seeing her face behind those shiny black rims was immediate and irrepressible. On the inside I was like a cat with a claw stuck in the carpet hissing and shaking and doing back flips. I wanted to take her right there by the thawing lamb chops on the kitchen bench!

Such forceful desire has only been present during two other periods of my life:

1) When Dad gave me a poster of a female rock star (I think Deborah Harry of Blondie fame). I hung it on the wall at the foot of my bed and there were several times I barricaded the door to focus completely on her, my body and mind screaming ‘Come Alive! Oh why can’t you just come alive?!’ like a test-tube-carrying Dr Frankenstein over his dormant monster.

2) In my early teens and right up until I met RM in a brick veneer home owned by an Anglican Minister in the tiny country town of Mortlake when I thought of sex every four and a half minutes (which I later found out was twice as often as the national average). Frequent in my 24/7 imaginings was the sultry, experienced, cunningly nonchalant woman who would take me under her wing and transform me from a pleading-eyed immature boy into a strong, confident, fully grown man she could treat as a personal love-slave.

I couldn’t get her glasses out of my head and texted many naughty things to her over the coming weeks including, 'Next date night you can be a student teacher and I’ll be your most disruptive student' and 'Or maybe you’re a librarian and you come to my house to collect the fine for some overdue books but on discovering I am very poor you suggest another way to pay it off' and 'Or maybe you can be a lawyer representing me on sexual harassment charges who decides I need to get a dose of my own medicine…'

The electricity in me passed over to RM. She started to leave the box to her eyeglasses around for me to find while she was at work and I’d open it to find clever little flirty notes that linked sex and eyeglasses together like, 'I’m going to make a spectacle out of you tonight' and suddenly we were there again, experimenting, flavouring our world with a different kind of spice, driven by the frenetic sexual intensity that’s more indicative of the very early stages of a relationship.

RM’s Optometrist had reached into my pleasure centre and turned the bulb on a faulty neuron to reveal a very important truth to me. Somewhere along the way, as the years had passed, RM and I had stopped experimenting; we had stopped trying new things.

Blinded by our nirvana-like couplings we limited ourselves to several intricate role plays, two pairs of felt-covered restraints, one Bonobo documentary we’d watched so many times we could recite entire scenes by rote, the entire marital aid section featured in the Sexy Land catalogue, and an abrasive beige-coloured Nana blanket. I could see, all of a sudden, that our fleshy paradise of thrice weekly genital satiating multiple-orgasmic sex had become our prison. And if fate hadn’t freed us – via RM’s headache-causing vision – we’d be there still.

This brings me to the kernel of what has inadvertently become an advice piece on how to have great sex in a long term relationship.

Complacency kills. No matter how great the rub, no matter how rewarding the stroke, you must always search for the new. You think you’ve done it all? You think the sex you’re having is as good as it can gets? You’re wrong. There’s a kink hiding inside you just waiting to come out. For me it was RM in a pair of eyeglasses. For you it might be your partner in a pair of riding boots, or a damp electric blanket.

Go. Find the key to your prison door.

How do you keep the spark alive in your relationship?

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