Emmanuel Macron, Brigitte Trogneux
Former French economy minister Emmanuel Macron attends a rally with his wife Brigitte Trogneux for his political movement, En Marche in Montpellier on 18 October 2016Jean-Paul Pelissier

Oh dear, oh dear, how to wade through this moral swamp? Extreme nationalist Marine Le Pen and a hitherto unknown chap called Emmanuel Macron come through the first round of the French presidential elections, with him just ahead.

Some French females, including professionals, think this is a victory for womanhood. These misguided sisters reduce the struggle for gender equality to the lowest common denominator. Le Pen, a very smart and persuasive women, has made her party respectable (and therefore doubly dangerous), but in this case, surely, anti-fascism trounces feminism. Doesn't it?

Macron is intellectual, ambitious, centrist, pro-EU, the youngest ever presidential candidate and clearly an exceptional political strategist. For anti-fascists and anti-racists, other progressives too, he is a saviour.

Millions of us are mightily relieved that he has the resolve and policies and support too, to beat the Front National in the second round. But his private life raises some awkward questions

Macron's elegant, lovely wife Brigitte Trogneux is 64-years-old, a grandmother of seven, and 24 years older than her husband. At a meeting after this first round he said: "Without her, I wouldn't be me." It is clear they are totally infatuated with each other.

Such respect and love could be seen as a real victory for older women of whom I am one. Older men frequently abandon their first wives and children and rush into the arms of much younger women – in fact it's a rite of passage after they hit 50.

The line is long. In recent years Jeremy Paxman, Rowan Atkinson, Ronnie Wood, and President Francois Hollande have joined it. But for women, the game ends at around 40, perhaps earlier. Young men do not go for us the way young women do for middle aged males. When some glam, famous ladies do get together with muscular lovers, they are mocked as preying 'cougars'.

So this couple, in some ways, can be seen as positive role models. But only if ethical standards are stretched to the point where they snap.

Macron and Trogneux have been married for 10 years. But they met in when he was a 15-year-old schoolboy in Amiens and she was his drama teacher. (Drama teachers! So easy to fall for when you are young and impressionable. I know I had a crush on mine, a Mr G, who fizzed with radical ideas and prized open our imaginations).

One British newspaper published a sweet picture of the youthful Macron giving his teacher a kiss on the cheek. She was married at the time and had three kids. Those who knew him then describe a student of "Olympian intelligence", older than his years, serious about life and education. On French TV last year, Trogneux said: "He wasn't like the others. He wasn't a teenager. He had a relationship with adults as equals."

But he was a teenager, albeit a precocious one. That is the thorny truth. And she was the adult and, furthermore, in loco parentis, as are all teachers and lecturers. Most such teenage passions pass. But in this case the boy never forgot his first unsuitable love after he left her school. He carried on phoning and, according to Trogneux, wore her resistance down, until she left her family and went off with him.

There is so much about her actions that I find unacceptable. First, she betrayed her husband and kids. Although time heals such fissures, they must have been shocked and hurt. Such treachery is cruel and unacceptable, for men as well as liberated women.

Secondly, she seemed not to understand the good, solid reasons why relationships between pupil and teacher, student and lecturers are regarded as improper and potentially exploitative. Murky shadows dim the light of this extraordinary love story.

What would our reactions be today if an upcoming, charismatic female politician was with a man who taught her at school? What if the husband said: "She wasn't like the others. She wasn't a teenager. She had a relationship with adults as equals"?

We would find it creepy and deplorable. Even pop stars – whose lives are ungoverned by rules – face opprobrium if they marry adolescent girls. Chuck Berry and Jerry Lee Lewis are forever seen as child bride snatchers. The same happens in politics. The rakish Tory Alan Clark married his wife Jane when he was 30 and she was 16. Though he had a good career, this marriage and his subsequent philandering blocked his progress.

Trogneux cannot expect the world to forget what she did for love. I feel rotten writing this, because it sounds so judgemental and also because I really want Macron to see off Le Pen.

I fervently hope he wins. Yet I hope too, he and his wife will be scrutinised and held to account more than they have been. The personal and political selves are indivisible.