It happened earlier this year.
It was a warm Spring morning and I was standing naked, looking out of my open, screened window at the small patio, just outside my bedroom. I was enjoying the pleasant breeze and planning to jack off standing up, which is something I often like to do.
I had already put a towel on the floor to catch my pre-cum and began slowly stroking. All of a sudden a man appeared just outside the window; it was a gardener who came in to trim the hedges from the inside. He looked at me, saw what I was doing and smiled. I could have stopped, but I needed to cum and I thought what the hell, if he didn't like what he saw, he could look away.
He kept watching me and that made me get harder, so I began jacking faster. Then he surprised me by pulling out his good-sized, brown, Filipino cock. He got it hard and started jacking himself. That got me more excited, so I started going faster and he did too. We watched each other for a while.
Then he stopped stock still. Nothing happened for several seconds, but then his cock suddenly exploded with a big load that went up higher than his head and fell to the ground several feet in front of him. Well, that did it for me and I had a great orgasm, blowing onto my towel!
He shook his cock, milked out the last few drops of cum and stuffed it back in his pants. He gave me a wink, another smile, picked up his shears and went to work. I stood there a while savouring the good orgasm I just had. Then I went to the bathroom and had a shower.
For several Thursdays after that I would stand by my window jacking off, hoping that he'd return. But I never saw him again.