He was still there when I returned about 10 minutes later, although this time he was standing up, nearly naked, and masturbating. He looked like he was in his 40s. My sons were young when it happened so I would have been in my late 30s.

I had sunglasses on. I ran past without giving a sign that I noticed what he was doing although it was clear his intention was to get a response. A few hundred metres further on was a carpark beside a surf club. I asked a woman if I could use her phone, rang police, complained about the man and walked back the way I had come.

It would be fair to say the masturbating bloke got a shock when he saw me standing there, waiting for him, wearing running gear and shoes and looking like someone who was prepared to call him out. Without his crown jewels in hand the bloke turned to water, even before I said anything.

He said “I’m sorry, I’m sorry, I didn’t mean anything” a few times before I told him to shut up because the police were going to have a word with him. That’s when he started running. I yelled out that he had bare feet, I was in running gear and if he ran a marathon I would still be just behind him.

So he stopped, walked back, said sorry another couple of times and we walked back to the surf club where a police car arrived within a few minutes. I told two police officers what had happened, gave my details and went home.

A police officer rang a few hours later. My memory is that he told me the bloke was a bank employee who didn’t dispute what had happened, although in his version he didn’t mean for anyone to see him.

I laughed and said he did everything but put up flashing lights and sound an alarm to make sure I didn’t miss him standing on top of a dune - the master of all he surveyed, in front of what he possibly hoped would be a shocked audience.

The policeman asked if I wanted him charged. I said no. I just wanted police to tell the man about another woman who sometimes walked up that beach a bit later in the day.

She was an older woman who had been raped only a year or two earlier while walking a few kilometres from where she lived.

I had run past the man and been irritated that he thought it was OK to include a complete stranger in his beach wanker fantasy, but nothing more than that. I wasn’t scared, shocked or even surprised because when I first passed him it looked like he had the potential for doing something more than just read a book in the sun.

But the older woman? It might have been enough to scare her from venturing out again.

I asked the policeman to tell the bloke that his “I didn’t mean anything” showed he hadn’t given the first thought to the fact his “audience” had a life and a history. In other words, that she was a person. It might have been the traumatised older woman. He mightn’t have meant to re-traumatise a woman who had been raped, but his failure to even recognise there were two people in his fantasy, and one hadn’t consented to anything, meant it might have had a much more significant impact on another person’s life than he could ever have considered. 

He lucked out by getting someone who felt responsible enough for the older woman that she went to the trouble of calling police, and who realised he might have got off on having someone just yell at him.

He wasn’t charged. I didn’t want him to be. Taking it to the length of ending up in court would have been too far. He was an idiot but I didn’t feel like a crime had occurred because I didn’t feel threatened. But I wanted him to think about it. I wanted him to know that a woman on her own will respond, but not necessarily in the way he was expecting. I wanted him to give a thought for the woman.

The issue wasn’t about public nudity or the act itself. Run on a beach regularly and you’ll see all manner of weird and wonderful things.

If he’d wandered up behind the sand dunes and had his way with himself I couldn’t have cared less. But he made his need for an audience a reason to drop respect for another person’s right to go about their business. A woman walking up the beach that day might just have experienced a death in the family, the loss of a job or the breakdown of a relationship. I don’t think I’m being unreasonable in expecting that someone in that situation should be able to have a quiet walk without being confronted by a thoughtless git and his shortcomings.

And would this bloke have dropped his pants if I’d been a man? 

There’s been a lot of debate over the past year or so about sexual harassment, sexual assault, power imbalances and gender struggles.

Germaine Greer was punished this week for saying she wanted women to react immediately to incidents like being groped on a train, and that women agreeing to sex with men like Harvey Weinstein to get a part in a movie was “tantamount to consent”.

Both statements can be challenged, of course, and were. Women like Greer whose careers have been about challenging sexism would call out a grope – and know what to do if it ended up being just a clumsy bump on a crowded train. But many women - and men – are more likely to hesitate in unusual situations and remove themselves rather than speak, and that doesn’t just apply to situations involving sex.

And the Weinstein allegations cover more than just a powerful man seeking sexual favours from younger women.

Quite a few people have pounced on Greer’s comments, or those of Catherine Deneuve and 99 prominent French women who said the #MeToo campaign against sexual harassment amounted to puritanism, and the right to “hit on” others was vital to sexual freedom.

I can’t support all of what they’ve said but I can support some. Sexual contact between men and women – or women/women, men/men – is often about nuance and shades of grey, rather than black and white absolutes, because ultimately it’s about communication. We need to remember that as we break new ground on sexual equality.