Yes, it happened to me 25 years ago. Very similar! And I am still trying to make sense of it.
I was 35 and in a very happy cohabiting relationship with a gorgeous, funny, kind man of 33. We'd just bought our first house together. Life was perfect.
One day I was standing on a station platform when a colleague arrived, put down his briefcase about 20ft from me, to wait for his train. He was about 48 and nothing special. As I looked at him, I felt suddenly excited, I mean sexually! All tingly and weak-kneed and breathless. That had never happened to me before and it never has since with any other man.
He got on his train and I got on mine, and I just HAD to go to the loo and um, well, I won't say what I did.
From that moment, I could not stop thinking about him. I sneakily found out where and when he was working and "accidentally" turned up, acted all casual, and just chatted with him till he had to go. Again, my body got majorly turned on even though he didn't lay a finger on me and we chatted about banal work things.
I was utterly powerless to stop thinking and fantasising about him. A female colleague was booked to go on a course with him and I begged her to surreptitiously get a photo of him for me, which she did. I'd never seen him without a hat before and it turned out he was completely bald on top. Oh, and sitting down he had a fat gut that I had not noticed. And yet I did not care about either of these things! I was utterly crazy for him.
I carried that photo with me everywhere, repeatedly looking at it, and it made my heart leap and my loins throb. When I could get privacy away from my partner, I took the photo to bed and, well, you know what.
The man left our workplace soon afterwards and I sobbed and sobbed, and still carried on using his photo for my w*nk-fodder.
It was a few weeks of utter madness. It was completely out of my control. I could have lost my partner, my new home, everything we'd worked for.