Head upstairs.

Trying my best to ignore the giggling coming from outside, I slowly made my way to the bottom of the stairs that were leading up to the bedrooms on the second floor.

As I got nearer, the unmistakable sounds of pleasure because louder and clearer. Someone was definitely having the time of his or her life up there. Was it mom? Or maybe it's Kristin having a last-minute masturbating session before heading to the cabin for the next few days. As my curiosity got the better of me, I found myself slowly making my way up the steps, creeping as slowly and as carefully as possible in order not to make any noise.

When I got close to the top of the stairs, I suddenly stopped. The reason for that was because I saw movement right ahead! I shifted a little to try to see better, and what came into view, between the railings of the stairs was a flash of red. It took me a while to register what I was seeing right now. Standing next to the railing of the stairs, my mom Sofia, was currently crouching outside my sister's room with her back against the railing. And because of that, from my position on the stairs looking up and between the railings, I was able to see clearly under her dress, and at her bright red, lace panties between her legs.

I stood there, entranced by the view for a few seconds before it suddenly hit me. Why was Mom standing here? Then I heard it again, the unmistakable sounds of moaning. It sounded like it was coming... from my sister's room!

I was right! It WAS Kristin masturbating! That naughty little girl!

Just when I thought that my guess was correct, I heard Mom whisper something that proved that I was far from it.

"Oh my god! My dear daughter, you do have your mother's luck! Finding a boyfriend with such a big cock! Almost as big as your dad's!"

Mom's words made me almost cry out in surprise. Firstly, I had not expected to be hearing details about my Dad's anatomy so suddenly. Secondly, what is this about Kristin having a boyfriend? If that had surprised me, what my Mom said next almost made me fall down the stairs in shock!

"Oh wow! That Patrick can really fuck! He's giving Kristin the fucking of her life. I wonder if they do it very often? Kristin is such a lucky girl! Oh to be young..."

What the... What is this absurb situation right now? Is Kristin currently getting fucked by this boyfriend that I have never seen before in her room right now? And is Mom sneaking outside her room peeping at the both of them?

Looking up at my mom's panties once again, I could spot the unmistakable movement of her fingers under the fabric. She was definitely touching herself while watching my sister and her boyfriend having sex!

Suddenly, I was tempted. Very tempted to have a glimpse of what is happening inside the room! As the moans got louder and faster, I took the risk and took three more steps up the stairs. I was now practically right behind my Mom. Thankful for my sister's loud moaning, and the carpeted steps to hide my footsteps, I peeked through the rails and between my mom's legs to see the scene inside my sister's room.

In the room, I saw two naked bodies on my sister's bed. Nearer to the door, my sister Kristin was currently on all fours as another young man with chiselled abs and a sharp jawline ploughed into her from behind. Each thrust he made into my sister caused her to moan and her perky breasts to bounce as I watched his long and hard dick entering Kristin's pussy over and over again.

I stood there, stunned, entranced by the look of lust on Kristin's face and her naked body. Her fair, smooth skin exposed to the sunlight coming in from the windows. I have not seen her naked body ever since we were younger when we took baths together. Seeing how her body had transformed over the years into one of an attractive, healthy young woman, I could not help but find my cock rising to the visual stimulation.

Suddenly, a soft but audible moan from above me caught my attention and I looked up and almost choked in surprise. Facing the extremely sexy scene in front of her, Mom had given in to the stimulation and spread her legs a little wider. Her fingers had pulled her soaked panties to the side and were now attacking her very swollen clitoris. Looking straight up between her legs, I was rewarded with a very closed-up view of her gaping pussy and the damp, musky smell of her sex.

Eventually, the speed of mom's fingers that were pumping into her pussy increased, together with the thrusting speed of the guy that was fucking Kristin in the room.

"Oh yes Patrick, just like that! Thrust that big, fat cock into me harder. You're making me cum!"

I held my breath and tried my hardest not to make any noise when I heard what my mom was whispering right in front of me. My attention momentarily caught in a dilemma, unable to decide between watching Kristin having sex and mom fingering her pussy right in front of me while fantasising about fucking her own daughter's boyfriend, I found myself reaching for the painful tent in my shorts, intending to release some of the pressure building inside when both mom and Kristin started shaking at almost the same time. Shortly after, the guy that was fucking Kristin also appeared to be having his orgasm. He quickly pulled out from Kristin and ordered her to turn around and face him. I saw Kristin doing as she was told, only for her beautiful face to be hit with a powerful stream of cum from the guy's cock right before getting a thick cock shoved into her mouth.

It was only at this point in time that I took the time and looked at the guy named Patrick. To my horror, I noticed that he was not looking at Kristin who was bent down in front of him, but he was looking at the door instead, at mom through the small gap in the door, who was still standing there looking at him getting sucked off by her own daughter. But that was not the most shocking thing yet. What Patrick did next, caught me and mom completely off guard as a cheeky smile appear on Patrick's face and he raised his hand to give a little wave towards Mom. I heard a sharp intake of breath from my Mom with her dress bunched up around her torso, her fingers still in her pussy and her large, supple breasts revealed out in the open while her own daughter's naked boyfriend grinned at her, taking in the sight of her exposed body with a naughty smile on his face.

Eventually breaking out from her shock, Mom quickly ran off into her room down the hallway quickly rearranging her clothes while I took the opportunity to quickly sneak back down the stairs, my mind still trying to recover from what I had just witnessed as I made my way back out of the house.