The dilemma I am 40, gay and happily married. I have great friends and a good job. A year ago I met someone through some friends. Nothing happened, we just went out for a few drinks and socialised a bit. But we really hit it off. We had a very similar sense of humour, as well as similar backgrounds. The guy was a bit younger than me, in his late twenties. I found him very attractive and I felt that he liked me too; he was very flirty a lot of the time. I think about him a lot. Way too much, probably. He moved away soon after (with his boyfriend) and although we have had a bit of contact (initiated by me) I haven’t heard from him for ages. I just want to know how to get him out of my head. I feel sad that I’ll probably never see him again, although I’m not so stupid as to have ever done anything to ruin my great relationship. But I miss him. We hit it off, had a laugh together, and I feel like there was a connection there. What do you think? How do I get him out of my head? How do I put it in perspective, see it for what it was and move on?

Mariella replies Lucky you. What does it feel like? There are plenty among us who would struggle to recall the deliciously unexpected and life-affirming thrill of pure, unadulterated chemistry. The queue of lifers out there (and the prison analogy is intentional) consumed with envy at your good fortune will be a long one. To have enjoyed that delicious frisson, however briefly, with nobody the wiser and without causing harm to those you love, is a blessing of sorts. To paraphrase the anthropologist Helen Fisher, whose Why We Love, Why We Cheat is a TED Talks hit, romantic love is not an emotion, it’s a drive that comes from the craving part of the mind and has a similar impact to cocaine. So struggling to shrug off your addiction is no mean feat.

Your encounter is an example of how our lives pivot on fleeting moments. I knew one day I’d have the opportunity to quote my favourite George Michael song and now at last here it is. “Turn a different corner and we never would have met,” he crooned with aching poignancy in a celebration and lament of the transitory nature of fate. But just because an opportunity presents itself doesn’t mean we have to act on it, nor is it compulsory that because our lustful thoughts have been inspired by one person they have to be consummated with the same one! If that were the case, the porn industry would shut down overnight and Hollywood not long after.

Enjoying the sensation of desire is a pleasure in itself and not always something we have to chase down and make visceral. So many of the best moments in life are those that remain unrequited, with a question mark forever floating over what might have been. I once danced with a man for the duration of one song and remember it still as one of the sexiest experiences of my entire life. That it never evolved further is probably why it remains so deliciously etched in my memory.

I danced with a man for just one song and still remember it

In real life we know what comes next: compromise, responsibility and the daily maintenance required to keep any relationship and, later, family afloat. I don’t mean to make it sound workaday; there are transcendental moments to be shared even in the longest-term unions. As cold winter draws in, or emotional challenges arise, I’ll warrant I’m not the only coupled-up individual glad someone has my back. That shudder of pure sexual electricity can be celebrated without being consummated, as valuable a reminder of our sexuality as what we have chosen to sacrifice for the comfort of cohabitation.

There is an alternative route where we grasp every opportunity that comes our way, making pleasure our prime consideration with little care for those we damage in its pursuit. Plenty of our species do seem to have decided that life is a free-for-all and each day has to be treated like a looting frenzy, a smash-and-grab through anything you can get your hands on that might please you or add that elusive sense of value to your life. It’s a fin-de-siècle impulse that’s likeliest to proliferate when the world is feeling like an unstable and unfulfilling place to inhabit.

The most decadent of dynasties mark their own demise in a descent into self-indulgence on an epically destructive scale – Nero, the court of Versailles, the Borgias. Will Tinder and Grindr prove to be our lyres? Wandering the ruins of ancient civilisations offers the chance to marvel at what they built but also offers a salutary reminder of what was lost. We too will pass and the more we succumb to our basest instincts for gratification the sooner we’ll make ourselves redundant.

One of the downsides of locking into a long-term liaison is that no matter what advantages it brings, it rarely continues to offer that magical alchemy that gets you wondering what it would feel like to press skin on skin. Being human often comes down to the tussle between biology and brain, and sexual chemistry is the clearest example. It sounds to me like you’ve got a good life, a great partner and a lot to lose for a rush of pheromones. How’s that for perspective?

If you have a dilemma, send a brief email to mariella.frostrup@observer.co.uk. Follow her on Twitter @mariellaf1