Ok folks as promised here's more. After i got it on with Mary (my mother-in-law) we cleaned up and went downstairs me deeply safised and to be fair a bit shocked and amazed either my wife or Marys husband suspected anything and the one time i got her on her own rest of the evening she said it was a mistake a one-off so we left it at that.So life went on and when we visited all was as normal and so i figured I was getting enough other pussy so let it go.Lucky for me this all changed about 6 months later at my wife's cousins wedding.I was having a great time even managed to score a blow-job off my sis-in-law and got to finger her with a promise that if we could get away from everyone i could have a shag ( I must tell you how me and wife's sis got together some time) but as luck had it it was Mary i had later not Claire (sis-in-law) or my wife I shagged later.Anyway it was just over half way though the wedding party when my father-in-law asked if i would go upstairs for his tablets which i did when i came down he said could i go up again as Mary had just left to go up and prepare the bed for him ( He had a stroke years before hence he not up to much so that was why he leaving party) and i just missed her.So back up and there she was i let us in and i sat down when she went to bathroom now what happened next i swear she did on purpose but she swears to this day was accident she had decided to change into more comfortable clothes for when she rejoined the party as outfit she had on for wedding too restrictive and she thought i had left when she came out of bathroom almost naked just bra and panties and never noticed me sitting until i was bit cheeky and commented on great view at first she was shocked but after she calmed down she said that are session months ago must have woke something in her and maybe we should have a go here and now so off with clothes and into bed and oh yes it was as good as first time even managed about 10 minutes this time and after we agreed to meet up at least once a month to have sex which we still at now she still a great shag and fit for her age (she is now 60) although are sessions are now every other month so will probably dry up soon but i enjoyed every session and hope lasts for a while yet