Ever since I was a little boy, I was used to being nude with my mother and being touched by her, say at bath time or getting into my pajamas and at the beach where kids never wore costumes, we were always naked. I had no embarrassment about this. She also used to spank my bottom when I was naughty. There was a kind of ritual to these spankings. She'd warn me when I made her angry that I was to be spanked but it always happened at bedtime. I'd take off my clothes and she'd sit on the bed and put me over her knee and whack me on the bottom a few times – and sometimes more than a few if she was really riled up - with her bare hand. Always her hand, never a slipper or anything. It stung but didn't hurt for long although I sometimes cried and when it was over I'd put my pajamas on and get into bed, all forgiven. By the time I was 7 or 8, I was already playing with myself nightly and it was always a special comfort to touch myself down there after a spanking but I didn't think too much about the link between my punishment and the pleasure I got. These spankings continued in exactly the same way until I was 13 or 14 and my cock had long since begun to develop and enlarge. The last one occurred when I got up from being over mom's knee with an obvious erection. She didn't say anything and I was a bit embarrrassed. After that, there were no more spankings and really I thought no more about them. To me, they had been a normal part of my childhood. It was years later, after I'd been married and divorced that I began to wonder if there hadn't been something sexual on my side or mom's in those spankings. Living alone, I was masturbating a lot and fantasising to spice things up and one night spanking crossed my mind and I associated it with mom. Quickly found I could have a very nice wank just reimagining being over mom's knee and getting stung buttocks from her hand. I realised that I had enjoyed those childhood spankings and then it occurred to me that maybe mom had too which is why they had gone on so long. I knew about incest now and although I wasn't sexually attracted to my mom who lived in another part of the country I was intrigued by the idea that we'd both got a kick out of these physical punishments. Which is why I hit on an experiment. I phone mom every weekend. The next time I called her I did it from my bedroom. I got naked and lay on the bed and rang her. I played with myself as we talked and steered the conversation round to childhood days which she always liked. I reminded her in a pretend accusing way of her spanking me and she laughed and said I'd sometimes been very naughty and deserved to be punished. “You surely don't keep a grudge, honey,” she asked. “It helped me let off steam at you too.” I now had a very hard cock indeed that I caressed but gently because I didn't want to cum while talking to her. But after I hung up, I grabbed my cock and quickly shot a big load right there on the bed.