When I was 19 staying at my aunt's beach house and they were gone so I took aunt's undies to masturbate. But my uncle came home early and caught me. He got angry and said he'd tell my parents. I begged him not to. So he said he would not tell if I wore the undies and rub my ass on his crotch.
I didn't know what to do. I thought that was a gay thing. But he insisted. So I did. I could feel his hard cock from his shorts pressing the my ass through the undie. He came in his shorts.
the next day he stayed at home and brought me some other underwear to wear. The same thing happened. We kept doing it while aunt was away. I started liking it and waiting for it.
One day he told me not to wear undies and just sit on his cock. I did. It was nice. Warm and full of precum he was rubbing it on my hole. Kept pressing it to go inside me but I stopped him. Just came on my hole.
Sometimes he would come in my room and lie on top of me pretending to fuck me. I like it a lot. We never fucked or sucked. Just that.