This story is true as well as I can remember it (except my name, of course). I was about 30 at the time, so the intervening 37 years may have blurred some of the details.
I was doing some community theatre when I received an offer to help me build a portfolio of photos for casting from a local director who 'specialized in all-male casts.' Naturally it was understood that meant he was gay.
He had a room he used as a studio where I donned various costumes and posed as imagined characters. That eventually led to posing in a posing strap, and finally, nude.
At one point I got a hard on but he said it was okay if I wanted some that way. He said he had a processor who would develop and print pictures of me with an erection. I had an idea I knew where this was going and was turned on by the idea.
So he proceeded to continue taking pictures of me and my hard cock, which turned me on even more.
After the photo shoot he asked if I wanted a 'back rub' and I once again thought I had a pretty good idea what that meant, and said I'd like that.
He started with me on my belly, and worked me over pretty well with skilled hands. As he worked on my thighs and glutes, I let him know that it felt very sensuous, and if he wanted to get even more sensuous that was fine with me.
He then slipped his hand between my legs and massaged my perineum, then slipping it a little farther and caressing my scrotum ever-so-slightly.
Then he had me turn over, and with my erect penis wagging in the air, continued to massage the rest of me, 'accidentally' touching my erection occasionally, and slowly working his way closer and closer to my loins.
I was literally shaking when at last he gave my trembling member a light deliberate caress. He was very subtle at first, increasing pressure and intensity slowly, staying away from the trigger point below my cock head and varying location, speed, and grip.
I wanted to see his cock, and asked if he wanted to take off his shorts. He did, but to my surprise he was flaccid. I tried a tentative touch but he didn't stiffen a bit.
By then I was too caught up with what he was doing with my penis, balls, and perineum to pay much attention to anything else.
I was aching to cum, and he said to just let it go. I did, as he finally began to caress my glans and rub the sensitive area below my cum slit, now expertly milking my semen out. I think I shouted when the first little jolt hit my urethra as my prostate clenched and a spurt of semen shot out onto my tummy.
The second spasm had it flying over my shoulder to land I knew not where, and my whole body writhed as he coaxed spurt after spurt of fiery spunk out of my gaping cock slit. At last he pumped out the last few dribbles, my loins aching from the workout to my prostate.
My penis was on fire still, and knowing me at that age I probably could have cum twice more with a little encouragement. But I was exhausted.
My belly, chest and pubes were drenched in the oleander fragrance of warm semen. I think all I could say was, 'Wow!' as he went to get a cloth soaked with hot water with which to wipe me down.
When he received the prints, seeing them turned me on immensely.
He asked if I was uncomfortable and invited me to strip. I did, and masturbated as I looked at photos of my own erect penis while he watched. He asked if I wanted him to photograph me masturbating and the thought was so exciting of course I said yes. I didn't last very long before I was squeezing out a great cum as he watched and clicked away.
We had many more photo shoots. He took some Ektachrome, and I brought a slide projector for the color slides. I'd get hard watching them and masturbate while he took still more pics.
He continued to give me an occasional massage and hand job, which I really enjoyed, but now mostly he photographed me masturbating and cumming. In all that he never seemed interested in reciprocation.
Sadly, all those pix are gone now.