I have read a number of stories concerning mother in law's so perhaps I could relate mine. My realisation that I fancied Betty, my mother in law began quite soon after I married the wife, Betty was a very well preserved 60 yr old, and possessed an enormous bust, with a slim figure. The years unfolded and nothing much happened , and I was left to fantasise about what it would be like to shag her. Occasionally their would be a glimmer of hope, like the occasion when she was cleaning some brass, and said to me " the harder you rub it the more it comes up", and once she commented about having seen a black man on a tv programme and was amazed at the size of what he appeared to have in his running shorts. Anyway time went on and my wife and I eventually retired to Wales, and Betty, who was by now in her 70's became a regular visitor, staying for weeks at a time. After a year or so, my wife was feeling that she had too much time on her hands and decided to take a part time job. This now meant that Betty and I were sometimes alone for the whole day when she visited, so my excitement was by now quite intense. On one such day, at about 8am after my wife had gone to work, I was lying in bed , gently tweeking my dick, when I heard Betty say from outside the bedroom, "can I come in" I felt dizzy with excitement and said "yes". With that the bedroom door opened and she entered saying " I am a bit worried, I have left some medication that I need at home and dont know what to do". "Don't worry I replied, we can ring my GP and get you a prescription", Betty was so relieved she came over to my bed and surprisingly kissed me full on the lips and said "your wonderful" To my amazement I heard myself replying,"can my willy have a squeeze" and then panicked at what I had just said. A moments silence ensued and then bliss, her hand slid under the sheet and firmly grasped my throbbing 7 inches, she rubbed it up and down for about 10 or 15 seconds then kissed me more gently again on the lips and said " are you sure you want to do this, Im an old lady". I assured her that it was something that I desperately wanted. She then undid her dressing gown , giving me the first sight of her massive breasts, that were sagging almost to her waist, and a nearly bald cunt with just a wisp of grey hair sprouting from the lips, but to me she looked glorious. The next half hour was the fulfillment of years of fantasy, culminating with an ejaculation that came from the tips of my toes, and leaving my dear mother in law lying along side me with a steady stream of come dribbling from her open fanny. Later that day, Betty had the usual remorse that most mothers would feel, and made it clear that their would be no repitition, and that remained the case. I now visit her in the reidential home where she is confined, and the subject is never discussed, but I think we both became a lot closer as a result of the experience.