Ok, so I'm a 17-year-old horny teen and masturbate regularly. I share a house with my parents, but I am an only child (aaaahhhh!) I love to stay awake at night and listen to my mum and dad have sex. My mum pants and groans and screams in ecstasy, and I jack off furiously just hearing them.
Anyway, this one night, I was lying in bed, waiting for the noises I expected. The usual happened, first I hear them whispering, then the bedside drawer opening, and then some laughing. I assume my mum gives my dad a handjob then, because I hear squelchy noises like lube, and he moans softly. Then more whispering, and then a big sigh from my mum, as my dad enters her. Their bed starts to creak slowly, and I unzip and pull my stiff cock out of my boxers. The rhythmic creaking continues, and after a while, my mum starts to enjoy it, and he's obviously hitting her spot, because she starts to breathe heavily, and moan quietly. Occasionally they stop, and my dad lubes his cock up a bit more, and they start again.
This night I decided to sneak out on to the landing to hear them better. As I opened my door, and moved outside, my mum's moans and groans became very loud, and the creaks in the bed were loud too. My dad would speed up and thrust really hard and fast, and my mum would be begging for more, and grunting in pleasure as he penetrated her soaking wet pussy. Her sighs became more intense, and she would cry out to my dad, telling him what to do, and that she was nearly there. I am stroking away on the floor, knowing that they are about to finish off. She starts to pant quickly now, whispering that she's going to cum real soon, and to fuck much harder. My mum suddenly struggles for breath, and screams in pleasure, as she reaches her amazing climax, and my dad grunts, and then collapses on to the bed. I'm sure it was mind-blowing when they came, as it was for me, with my throbbing seven-incher in my hand, having just shot four ropes of cum on the floor.