Did not know different...
I grew up in a normal house kind of secluded from any un-wanted attention. The way my parents worked at the time gave me a lot (A LOT) of time to be by myself and please myself. Being young I had no idea what I was doing I just knew that doing it felt very good.
My first time if I recall I was laying on my couch late at night with my penis hanging out laying on my stomach. I found that moving my hips side to side felt good so I kept going. I kept going faster and faster when finally I came. It was a dry orgasm but I didn't even know what jizz was yet. So I did it again and it felt even better.
After finding out this great feeling I did it everywhere, bedrooms, floor, couch, chair, car. I loved it so much I would (what I called wiggling) for hours a day. Reaching 20 orgasms a day was not un common.
Then after my sister got older. I took on the duty of teaching her the same way I did it. We still bathed together so we were not unfamiliar with what we both looked like down there. Not knowing any better we were sitting together on our couch watching TV while my mom slept and I pulled my pants down and started to rub the back of my penis against the couch. (still not old enough to make sperm so no mess was nice) my sister asked 'what are you doing'. 'I don't know but it feels really really REALLY good want me to show you'. She after watching me have a few orgasms said sure. 'OK I guess take off your pants and underpants' I said still humping my couch. 'OK now take your couchi and rub it on the couch like me' I reached my fourth orgasm of the day as I said this. She hopped onto the arm of the couch and asked what should I do. I gave a little laugh and showed her. After she got the hang of rubbing her lips on the couch we both started to do it together. After a few minutes I asked her how it felt. I opened one eye to look at her and she was head tilted back eyes closed moaning with pleasure said what. 'I said how does it feel?' ' oh, it feels good.' she said followed by a moan. We went for a little while longer, after yet another orgasm I ask 'did you get to the point were it feels great all of a sudden?' ' no not yet' she said with her breathing quickening and deepening. Then all of a sudden she moaned loud and squirmed about on the arm of the couch. I looked at her and smiled 'did that feel great or what?' while catching her breath she said' oh yeah' we didn't know it but she clearly had an orgasm.
That whole morning we humped and humped and humped the couch like it was or last day to live. We came and came and came all morning. We even raced each other to see who would cum first. This went on for hours, at least 5 hours that day. Unfortunately we heard the shower running and we got dressed as fast as we could so my mom wouldn't find out what we did that morning.
I hope you enjoyed this story. It was all true by the way.