I was in a great mood bowling along the highway just below the speed limit, windows down, wind blowing my hair and Ravel's Bolero blaring from all four speakers. I was running a couple of hours early, on my way to pick up Mom from my grandparents' house, where I had dropped her the night before to help with the housework, so I was in no great hurry.
Most Saturday mornings I usually worked overtime before going to collect her, but today was different. When I arrived to start my shift at the town's only electrical store, I found that someone had rammed a truck through the store front overnight, and cleaned out everything easily carried and just as easily sold, and the place was swarming with cops, so after they had taken a statement from me I had been sent home.
This suited me fine, because it was a perfect day for a drive, certainly too good to waste indoors. Besides it would be nice to spend some extra quality time with the oldies, and maybe see if needed any odd jobs sorted out. Parking the car in the driveway, I went inside and found Gran dozing in her overstuffed armchair, she opened her eyes and beamed at me when I gave her a peck on her wrinkled cheek.
"Hello Max, I must have nodded off. Is it that time already?"
"No Gran, I'm early. Someone crashed a truck through the door at work and robbed the joint, so they sent me home. I thought it would be nice to have a bit more time with you and Gramps." I looked around. "Where's Mom?"
"She's in the shed with your Granpa. I think she's helping him sort the place out."
"OK, I'd better let them know I'm here."
I let myself out through the back door and made my way to the shed, but before I reached it I heard Mom's voice coming through the open door.
"Plenty of time Dad, Max won't be here for a couple of hours yet."
Curious, I peered though the dusty window and my whole world turned upside down. She was leaning against the workbench, with her tee shirt and bra tucked under her chin, and her jeans and panties around her knees. Grampa was behind her, squeezing her bare tits as he jammed his cock into her.
"I don't know what I'd do without you Maisie," he puffed, "I really need you now that your Mom has lost interest."
"I need you just as much Dad. You have no idea how lonely I get sometimes."
I hated seeing what Grampa was doing with his own daughter, but I couldn't tear my eyes away as her pussy lips opened like a flower each time he pushed into her. There was a heavy lump in the pit of my stomach as I watched him fuck her, until he gasped and shot his load inside her.
She remained leaning over the bench, as she recovered her breath after he pulled out, and I could see globs of cum oozing from her puffed up pussy, and even though she was my Mom it was the most erotic sight I could ever have imagined. Finally she straightened and turned to him, pulling up her panties and jeans, and covering her tits as she kissed him firmly.
"Thanks Dad, that was lovely."
Now that there was no longer anything to see, I became afraid of being caught spying, and I beat a hasty retreat back to the house, where I dropped into a chair, fighting the sudden feelings of nausea and confusion.
Gran looked at me with concern. "Are you OK, Max? You look a little pale."
I tried to think what to say. Obviously I couldn't tell her that I had just seen her husband fucking their daughter, so I pressed my hand to my stomach and shook my head. "I just feel sick all of a sudden," I groaned. "Maybe I should just get Mom and go home."
It was another fifteen or so minutes before Mom and Gramps came in, both looking like the cat that got the cream. Mom looked at me uncertainly. "You're early Max, I thought you were supposed to be working this morning."
I explained about the work robbery, then told her I wanted to get home because I wasn't feeling too well. She offered to drive, then looked at me sharply when I answered with a curt "No."
I was seething inside during the drive home, and although she tried to make conversation I was too angry to respond, and she fell silent.
As soon as we arrived home I turned towards my room, but Mom called me back. "OK, Max, what's eating at you? It's more than just a belly ache, so tell me. Are you afraid they might suspect you of being involved in the robbery?" I shook my head, not trusting myself to speak, and she asked again, "Then what is it?"
Clearly she had no intention of letting it go, so I glared at her. "Why Mom?"