Six years ago I was dating a girl (I'm now 29 and married to someone else) who was so hot and very horny in bed. On a quiet Sunday morning after I'd stayed over at her parents home, we both thought her mom and dad had gone out. I slipped into my girlfriends room and In the process of fucking her ass from behind, her mom walked into the bedroom. Strangely she didn't go crazy or start shouting, all she said before walking back out and closing the door was "Enjoy her butt son, she's got one hell of a tight ass". The next week I called by still confused, but horny after my girlfriend had text me her parents were out. When I got there the door was open and on the mat was a note which said "Come upto my room I'm waiting". Getting there and opening the door, I came face to ass, as it were, with my girlfriends moms ass. She was knelt on her daughters bed naked and she playing with herself. "It's yours if you want to fuck it". Was all she said, and stupidly I did. From then on if I wanted to fuck her daughter as she put it, I'd have to fuck her asshole too. I carried on having sex with them both for over a month, but soon started to hate fucking my girlfriends mom, and reluctantly I dropped them both. Three weeks back, enjoying some sunshine in my back yard, I noticed the new occupants were moving in next door. Looking up as my wife handed me a beer, I saw someone looking my way from over the fence. It was my old girlfriends mom and she had the biggest smile you'd ever seen, as she went on to say hello and tell us she was our new neighbor. I couldn't believe she was moving in, and not only that, she was moving in alone after divorcing her husband. The last three weeks have been a series of her calling by when my wife goes out, or talking to me over the fence if I go into the back yard. And all her inuendos are about me fucking her asshole again, hinting my wife wouldn't find out or giggling saying she might. So What the fuck should I do?