It was still early evening when I came home from my friend's place. The house was unusually quiet. I didn't see Mom or Grandpa anywhere. So I went upstairs towards my bedroom. My parents' bedroom was at the end of the corridor but the door was open and a light was on. I was curious and so I went near the door to see if Mom was there. What I saw stopped me in my tracks. On the king-size bed Mom and Grandpa were sleeping together without a stitch on. When I went closer I could see Mom lying on her left side in a fetus position and Gramp was right behind her in the same position but his ass was moving back and forth slowly.
I went even closer and what I saw was so shocking I stood there for a couple of minutes not knowing what to do. Gramp had his cock inside Mom's cunt from behind and was slowly fucking her even as they slept. But soon the excitement was picking up and Mom started to push her ass back into Gramp's crotch and a slow rhythm was set. Gramp now moved his right hand on Mom's chest and began squeezing the right boob. That made Mom moan and push her ass hard on Gramp's cock.
Soon both of them were moaning in their sleep. Then suddenly Gramp got hold of Mom's waist and plunged his rigid cock fully into Mom and groaned loudly as he filled her cunt with his spurting cum. Mom kept her ass pressed onto Gramp's crotch and came too- ungh, ungh, oh, oh, fuck, oh fuck, fuck Dad, fuck! Only when both their orgasms were done did they open their eyes.
Both of them noticed my presence at the same moment and a look of utter shock spread in their eyes. Mom got her voice back first and said, "what are you doing here, Mintu? How long have you been here? How come you are home so early?"
I replied, "Mom, calm down, it's I who should be asking the question – what are you two doing? Well, I can see what you are doing, but how did it happen?" Mom didn't answer right away but she noticed that I was totally naked and my 8" cock was stiff like a bone and pointing at her.
Mom smiled and said, see Dad your grandson has grown up." Gramp said, oh baby, he's grown up alright and I am sure he is dying to get into the slippery heaven that's between your thighs" Mom smiled at me and said, "come son, come to Mama and show me how grown up you are."
I approached her as if in a dream. Mom got hold of my cock and pulling me by it lowered her mouth over it and I felt her moist tongue over the tip licking away the pre-cum that was already oozing out sending shivers down my spine.
Gramp was lying on his back with his limp cock still shiny with their combined juices. He said, "its for the best that he found out, Husna. You'll need a young cock to keep your hot cunt satisfied." Mom said," I'd love to have him inside me if he wants to fuck his old Mom". I blushed, and said, "oh Mom you don't know how many times I've fucked you while masturbating."