I had always had a 'thing' about my older sister. She grew up into a big busted woman, and left home in her early teens. Now we are both in our fifties. We hadn't talked or written to each other for many years. I can't even remember how we got back into contact.
Sex drifted in and out of our letters, casually at first. My lover at that time used to have fun making home movies of our sex. I made no secret of this to my sister. Soon she was asking me to send her tapes. The thought of my sister watching me and my lover was really hot.
Soon after a letter arrived with photographs. Neither of us were any kind of beauty. I had quite a big belly, and large breasts, for a man. Her large pendulous boobs hung down to her waist. Her belly fold almost completely covered her cunt. Her butt was big and merged with stocky thighs. But she still excited me!
I wrote her a letter telling her how I jerked off to her pictures. Her response was to describe how she stimulates her ass and cunt with various objects. Next we were exchanging porno stories that we made up. We both wrote about how wet and horny those letters and pictures made us. Things have simmered down for now, though we still discuss our sex lives openly.
I have an art gallery of her in various poses, and jerk off to them on a regular basis.
P.S. my lover likes to look at them too.