I was at home for a day and everyone else was either working or at school.  I had to swing over to my mother-in-law's house to pick something up for my wife. When I went in, she was in the living room by herself watching tv.  She turned off the TV, and asked me to come and sit with her.  She knows that things aren't great between me and my wife and was telling me how she felt bad that I had nobody to confide in.  She moved closer and sat up against me and hugged and cuddled up to me.  She brought her face right up to mine and told me that she could be trusted not to let any of this get back to my wife.  "everything that happens or said here stays here". She hugged me close and tight, her breasts were pressed tightly against my chest. Our bodies stayed together while she again looked me in the eyes and said "this is a safe place where you can relax and feel safe" Her hand touched my leg and rubbed it smoothly. My hand moved to her breast and brushed against it, I gently cupped the side of her breast.  Her hand slide up my thigh. My dick hardened in an instant and bulged against my loose fitting pants, there was no hiding it.  She looked down and again back to my eyes and aid "if we do this, we mustn't tell anyone. Ever." I agreed. She immediately took her panties off as I removed my clothes. She slowed me down and started stroking my cock and said "slow down honey, nobody will be home for a few hours, we don't need to rush. It seems like neither of us have had a great sexlife lately,let's take our time and enjoy it." She pushed me back against the back of the couch and swung ler leg over me. My dick was only an inch or so from her pussy and I could feel that she was warm and moist.  She moved into her position and gently lowered herself to touch her pussy to my cock.We locked eyes again and both nodded to each other to acknowlege the act. She lowered herself on to me and slid all the way down my shaft.  I was completely inside of my mother-in-law, her pussy ground at the base of my cock.  She started to fuck me while she hugged me tight. The two of us moved perfectly together and she soon began to climax. She planted herself down on me and ground out an intense orgasm that shook her to the core. She got off of me and sat back against the couch and spread her legs to me. She invited me to fuck her just like that. I moved in and was soon pounding her pussy like I was a teenager again.  She slowed me down again and held me close to her, and made me fuck her slower. Her hand was on my ass while I fucked her. She slide a finger into my ass! At first I wasn't sure about it, she whispered "relax baby, I won't ever hurt you." I did relax and she started to finger my ass while I fucked her slowly. A second finger joined in and she began to massage my prostate while I fucked her well.   The feelings all came crashing together, the release that started deep in my loins erupted as I began to cum.  She pulled me all the way into her as she continued to finger my ass as I came.  I was all the way in when I released deep inside of her.  I fucked her deep and bounced on her to feel the orgasm from my cock and my ass at the same time. The resulting orgasm was the most intense that I ever had. A while later I left.  As I was leaving she huged me in the doorway and said "that was a beautiful thing and nobody else needs to ever know about it" I nodded in agreement.  I headed out as she wave and said "have a good day! see you soon. As I drove off, my cock was still hard as a rock.  I had just had the most amazing orgasm of my life while fucking my wife's Mother.