Jerry is a man I worked with. In fact, I was his boss in our small office of half a dozen people. It is rarely that I am attracted to a man in real life but Jerry was an exception.
Often, it’s a small and relatively trivial thing that arouses unsuspected attraction in either sex. Once for me, it was a mere glimpse of a girl’s bare ankle between her shoe and the cuff of her jeans. With Sarah, who was usually enveloped in baggy sweaters, it was unexpectedly and very briefly seeing her braless in a loose t-shirt and being aware of her breasts shifting slightly under it when she moved.
With Jerry, it was the sight of his hirsute shin when he crossed his legs one day in the office. Why that did it for me I don’t know but that night, in bed, I thought about him while I was masturbating, imagining that he was there watching me. Very soon, I was creating ever more elaborate fantasies of him exploiting my desire and using me as a sex toy.
Being a sex object is an important part of my masturbatory fantasies. I thrill to the idea of the mistress being submissive to her maid or the master being sexually humiliated by his servant. No doubt the fact that Jerry was my subordinate contributed to my attraction to him.
Jerry was married – as was I – and I dreamed of supplanting Alma, his wife, in their marriage bed.
In my fantasies, in which I still indulge, he always plays a dominant role and I am unquestioningly obedient to him. He takes me home when Alma is away and instructs me to get nude and masturbate in front of him.
In other scenarios, he takes me up to their bedroom and I put on Alma’s underwear and stockings and again masturbate for his amusement that I should be prepared to abase myself so openly while he watches.
Best of all is when we get into their bed together, Jerry nude and me wearing Alma’s nightie and he makes love to me as if I were a compliant girl.
We exchange long, soft kisses while his hands roam my body under the nightdress. Sometimes, he straddles me and pushes his beautiful penis into my mouth. Other times, he turns me over, smears a generous daub of lubricant in and around my anus and then slides his penis inside me.
I feel him pound me with short, deliberate jabs of his pelvis against my buttocks and then the sublime hot gush of his cum deep inside me. 
At moments like this, I’m overcome by the certainty that being fucked, having my yielding body entered and owned by another person, is absolutely the most profound sensation I could ever experience.
The wanks I have with these fantasies are among the most satisfying as I have ever had in more than 60 years of very intensive masturbation.