I was on holiday with my wife and mother-in-law (she is in her 70's). We were in a caravan in Cornwall, UK, and my wife decided to go for a dip in the pool one morning. So leaving me in bed she set off to the pool, I knew she would be gone for a good hour or so, and I was feeling really horny, so I decided to masturbate whilst she was gone, forgetting that her mother was in the next room and that the walls are very thin. Anyway, I was stroking my cock for about twenty minutes, taking myself to the edge of orgasm then stopping, which was making me moan loudly, at this point I decided to make myself cum, and brought myself to a very powerful and noisy climax, shooting hot cum all over myself.
After I had cleaned myself up with some tissues, I put on my robe to go to the bathroom and shower, my mother-in-law was sitting in the lounge area and said 'feel better now do we' I said 'sorry, I'm not with you?' she said 'I could hear everything and you were masturbating, you were obviously very frustrated judging by the sound of your orgasm' I went bright red and apologised, she told me not to be silly and that everyone masturbates, but told me to let her know when I was feeling horny again and that she wanted to 'supervise' my wanking sessions from now on, at this point she asked me to take off my bathrobe so that she could see me nude, even at 48 I am in good shape, as I have been into weight training and fitness my whole life.
So off it came and she sat and looked at me and to my own surprise, my penis started to become erect again, after about 30 seconds I had a full erection and she asked if she could feel it. Walking towards her, my cock bobbing in front of me, she felt me up, we said nothing for about two minutes whilst she cupped my balls and pulled my foreskin back and forth over my knob end. I told her I wanted to wank off for her and she let go and told me to kneel right in front of her and begin masturbating. I could not believe she wanted me to do this, but I did as I was asked and began wanking off for her. She placed a saucer in front of me on the floor and said that when I was ready to cum, I was to let her know and that I had to cum on the saucer.
After five minutes of this I announced my impending orgasm, pointed my cock at the saucer and shot a full load onto it, she clapped and cheered as I did this in front of her. When I was finished cumming, she said 'good boy, a nice big load for me, now lick it up' and lifted the saucer to my mouth and said if I didn't she would tell her daughter what I had been doing. I did as I was told and swallowed my own cum. That was two years ago and she now 'supervises' me about three to four times a week. I don't always have to eat my cum, but I do have to be nude the whole time I am at her house doing 'odd jobs' for her, she may be old but she knows how to keep a man in his place.