Remember Rear Window, the old Alfred Hitchcock movie?
Jimmy Stewart was stuck in his Manhattan apartment with a broken leg, and observed love, angst, creativity, and even murder through his, yes, rear window.
I mostly saw sex through mine.
I was still a bit new in NYC in the early '80s. Had a 5th floor walk-up in a slummy building. It was a classic illegal sub-let. I was young, broke, and lonely.
But I had a really great rear window.
One evening, quite by chance, I saw two people fucking in the building next door, accross the air vent. Woof!! I was glad that I hadn't turned the kitchen light on.That 4th floor bedroom and its king-size bed were eight feet away. A red-haired girl was astride a blonde man. She was twisting and writhing on his cock. And I could see it all!
I spat in my hand and began wanking my dick. They were very hot. She threw her head back, thrashing her long thick red hair. The three of us came at nearly the same time, and my cum adorned the windowsill.
Next day I got a stool.
Every night they put on a show. Every night I wanked off.
After a few weeks I realized that I could use Blondie and Red to get laid. I got a second stool and asked girls in bars if they wanted to watch some live sex. Many said yes.
At first I just rubbed my dick through my jeans before jumping them. Later I pulled it right out and invited them to wank off, too. It saved time. The ones who came to see always joined in. Watching Blondie and Red fuck was very exciting.
Then Blondie and Red broke up. He got the apartment and had a steady stream of women. The times became unpredictable, but I already knew several interested ladies whom I liked, so I managed fine.
And the variety was fun. At first he had a different girl almost every night, but then he settled down to some regulars.
There was a very cute east-asian woman with cherry-red nipples and a mere whisp of black pubic hair. She liked getting her toes sucked. Alas, I couldn't see that too clearly, given the angle. But I could sure see her cum.