I appreciate that trying to form cohesive thought around something Donald Trump says is, in many ways, a thankless task. But through some mystical series of events, there is an actual chance he might become the leader of the free world, so I suppose I should get used to writing think pieces around his thoughtless and misogynistic comments. 

During last night’s US presidential debate - which apparently had ‘no clear winner’, presumably because Trump managed, for 90 whole minutes, not to insult women or make a bigoted remark - the Republican candidate said that he'd chosen not to make reference to Bill Clinton’s infidelity. 

He was asked, after the televised event, why he had made this decision. His response? That he'd thought about it, but decided not to out of respect for Chelsea Clinton, who was present in the audience. 

Oddly enough no-one asked Hillary if she was tempted to mention Donald’s three marriages, or that his first wife has claimed sex with him made her feel ‘violated’. Clinton didn’t even chuck in any throw away comments about the accusation of child rape that was filed against him at the beginning of the year (something the Trump campaign has denied and says should be ignored). She avoided ad hominem arguments, but no-one felt the need to quiz her afterwards about why she had done so. 

Trump had an opportunity, last night, to do the decent thing.  If he'd told reporters that no, he didn’t feel the need to mention the Clinton’s marital disharmony because it wasn’t relevant, it would have shown some shred of respect for the impressive woman he is running against. 

But of course he didn’t. And his attitude sadly reflects a wider problem with how we view infidelity.

Hillary Clinton might have political experience, an incredible education and wonderful family, and she might also be the most qualified candidate for the White House. But what keeps rearing its head again and again? 

The fact that she couldn’t keep her man in check. That’s her weak spot - and Trump, as well as the US media, just can't stop picking at it. 

It’s an attitude I’ve encountered over and over again in my role as a sex writer. A man cheats on his wife or girlfriend, and somehow the question people ask is ‘why?’ 

What was so abhorrent about her? What did she do wrong?

'The fact that she couldn’t keep her man in check. That’s her weak spot' CREDIT:  ANDREW HARRER/BLOOMBERG

Liz, 29, who broke up with her boyfriend of six years when she found out that he had been having an affair, told me that while people were sympathetic, they still pointed the finger. 

“My friends would ask if we had been happy, if we had been having sex, and if I’d been starting fights. I know they were just trying to find out if the affair had come out of the blue and wanted to be supportive. But the overriding message was that it was my fault and that if I’d been different he wouldn’t have slept with anyone else.” 

The problem with this attitude, apart from being totally unfair, is that it puts women in boxes. If your other half cheats on you you’re not just a victim of something horrible, you’re somehow sexless or aggressive. What other explanation is there? Instead of believing that a woman has been cheated on because the person they were dating was an arsehole, instead a narrative is woven to make it her fault. 

“I didn’t tell people that my ex cheated on me” my friend Maya, who is 32 and divorced told me. “When I started dating again, I just said we’d split up. I felt like when I said he'd  cheated, people started to assume things about me - that I wasn’t good enough or that I was a nightmare to live with. 

"I’m seeing someone now and he still doesn’t know that my ex had an affair because I’m scared he might think about me differently if he knew.” 

Being cheated on is humiliating and painful. And once you start to recover from the betrayal? There’s the pain of realising that people are judging you for it. For some women, like Maya, it means losing out on a second date. For Hilary it might be an excuse for voters to chose an under qualified and inexperienced presidential candidate. 

America was furious when Bill cheated. I don’t pretend to understand the puritanism of impeaching a man for getting a blow-job, at least it was his own actions that were causing Bill Clinton to suffer. But Hillary? She’s done nothing. Nothing but build a family, a career and a legacy. It would be a  crime if even one single voter considers her husband’s infidelity when it comes to deciding who should be the next leader of the free world.