Why do we always have to fight before sex?

I am 28 and I have been with my boyfriend for two years. We have great sex, but it normally follows an argument.

I am worried the chemistry between us is inauthentic. How can we get fired up for sex without shouting at each other first?

You are clearly worried by the possibility arguing has become a sexual trigger, but don’t get too hung up on that idea. Some couples thrive on the volatility that most others would find exhausting.

Within the context of an otherwise stable relationship, there is more evidence that arguing is healthy than there is to the contrary.

Studies of married men and women have found couples who express their anger have greater marital satisfaction and relational efficacy than couples who withhold their feelings.

When E Mavis Hetherington, professor emeritus of psychology at the University of Virginia, carried out a study of 1,400 families — detailed in For Better or For Worse, Divorce Reconsidered in 2002 — she concluded how couples argued not only determined their risk of divorce, it also helped to predict physical and psychological problems.

Hetherington classified marriages, and she described couples like you, who function at a level of extreme emotional arousal, as “operatic”.

Such couples are “intensely attracted, attached and volatile, given both to frequent fighting and to passionate lovemaking”.

Though this description suggests a degree of instability, Hetherington found people in operatic marriages reported the highest level of sexual satisfaction.

Physiologically, arguing and sex should be incompatible. In times of stress, the body’s fight or flight response triggers the release of cortisol into the bloodstream.

This constricts blood vessels supplying non-essential organs such as the genitals in order to pump more blood to the heart and lungs.

Technically, this “vasoconstriction” should prevent sexual arousal and certainly, in the face of serious threat, anger and fear will suppress a sexual response.

However, the physical manifestations of heightened anxiety are very similar to arousal; in both states, heart rate increases, palms become sweaty and you become more alert — and when a degree of moderate anxiety is coupled with erotic promise, the brain misattributes these symptoms to sexual anticipation and arousal is heightened.

It is a question of degree. Obviously, regular fights which leave lasting emotional or physical scars are evidence of a dysfunctional relationship that needs to be terminated, but verbal jousting or political disagreement can be a positive opportunity for one or both partners to get attention, to show off, to flex intellectual muscle and, importantly, to demonstrate autonomy.

One of the tenets of psychologist Esther Perel’s book Mating in Captivity is the idea that “eroticism doesn’t come from intimacy, but from distance”, and quarrelling can be a healthy reminder that we don’t own our partner and that we could lose them if we overstep the mark.

Perel says: “Anger highlights separateness and is a counterpoint to dependence; this is why it can so powerfully stoke desire. It gives you the distance you need. As a habit it can be problematic, but there’s no denying that it’s a powerful stimulant.”

At the core of every habit is a simple neurological loop which consists of a cue, a routine and a reward. Your current “cue” for sex is any minor or major disagreement.

Your “routine” is the way you allow these issues to escalate into conflict.

And your “reward” is sexual climax; the release of a neurochemical cocktail that counters the effects of cortisol and adrenaline and leaves you calm and content.

Because cells that fire together eventually wire together, the more you repeat this pattern, the more you strengthen the neural circuit.

Breaking it requires you to become aware of the cues that trigger the loop. Ideally you should both agree to do this, but you can reconfigure this aspect of your relationship by yourself, by creating new triggers for sex.

This is more difficult than fighting your way into bed because it involves talking about what turns you on, or off.

There are gender differences in the types of sexual cues to which men and women respond but , unsurprisingly, research shows both genders respond to “intimate talking” and “touching”, as well as simply “asking for sex”.

You could also try engaging in activities that will increase your levels of adrenaline without causing conflict. Virtually any activity that raises your heart rate — exercise, adventure sports, dancing, action movies or horror films — will heighten your levels of arousal, and mean the great sex life which you mention can happen more often, and not just after fights.

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