My son and I had been doing it for approximately a year when one night we found ourselves at my mother's.  My father had passed away the year before from prostate cancer and she was on her own at the time. When we'd come to visit, I'd worn a sexy pair of lycra with a thong.  I don't know if my mom noticed that or not, but Zachary had and was his typical lusty self.  His hands happened to find my curvers and pantie lines and without innhibition rubbed his hands all over me and pulled me towards his mouth and cock.  Mom pretended to be oblivious to the whole thing.  And I will say, my son respected his grandma and was mostly a gentelman though his hands and mouth were all over me. 

Her house has two bedrooms, one for her and one for us.  When nighttime came it found him and me under the sheets together.  Moving about the bed creaked horribly and I was concerned she could hear us from the room next door.  Naturally, I wanted to get fucked dearly by my son, feeling his familar dick slide deep inside of me, yet this led only to the sound "squeak, squeak, skreek'.

Being the clever guy that he is he laid me on the floor next to the bed as I whispered, "She can still hear us".  Fortunately there was a rug that my son had dragged my naked body onto.  He was sensitive to his grandma's hearing the bed squeaking, yet insisted on having his mom's pussy before he went to sleep.  Besides, I had already been vocalising enough for Mom to hear us  as he had been fingering me and eating my pussy up to now.  He put my legs in his arms, found my wet hole, and shoved his hard cock deep inside of me, penetrating me deeply while giving me the sensation of being fulll of his dick. 

When he was all in I cried out, "Oh fuck, Zachary!"  We both said it at the same time, "Fuck!", which I'm sure she heard, "Oh fuck, Mom!  I love your pussy.  If feels so good!".  Her grandson doing things to her daughter that are largely forbidden by society, yet so sweet that its a shame others don't try it.  He loved on me for about forty five minutes and orgasms later we were spent.

The next moring my pussy was still leaking my son's cum even after I'd gone pee.  I was all aglow when she said, "Your breakfast is ready, Susie.  Where is Zachary?"  "He's still sleeping, mom.  I wore him out yesterday.", I said as she gazed at me with puppy dog eyes.  Then added, "Thanks mom.  He'll join us soon.  If not, I'll go and wake him up."