Life was going pretty well after graduating High School. I decided not to go to college and instead focus on going straight into work, however I still didn't have enough money to move out on my own, meaning I was still staying with my family, including my step sister, Mandy.
Mandy was absolutely gorgeous, and it was so difficult to treat her as if she was my step sister. Every time I'd see her post an Instagram selfie, or a TikTok, or simply walking up the stairs behind her my cock would immediately get rock hard.One day during the summer, while scrolling through Instagram stories I spotted a picture she had posted of her in a sexy little bikini, I hadn't jerked off in days and seeing her show off her luscious curves made my cock shoot up towards the ceiling as I laid on my bed.
I reached over, squirting some lotion into my hand as I began stroking my cock while gazing at the phone, imagining the perfect fantasy of my walking right up to her, pulling the bikini off and fucking her right in the hallway of our house. My mind was wondering so much, imagining how she would talk dirty to me. Then all of a sudden I was pulled out of my wet dream as my bedroom door started to open. I could hear Mandy talking as she opened it while asking "Hey, do you know where the beach towels are?! OH!"
I was caught in complete shock, as was she. I didn't even realize I hadn't locked my bedroom door, so I tossed my phone down and reached for a pillow to cover myself. Before I could turn back to the door, Mandy was quickly stepping out and shutting the door behind her while yelling "SORRY! I SHOULD HAVE KNOCKED!"
My heart was pounding as my cock felt like it was curling itself up inside my body. I sat on the bed for nearly half an hour waiting in horror for a phone call from either my mother or from Mandy's father, thankfully that never came. I finally took the pillow off my dick, seeing it covered in my hand lotion. I got up and quietly stepped out into the hallway, making sure Mandy or our parents were nowhere in sight as I walked to the laundry room to put the pillow and some of my clothes in the washer. From there I went right back into my room, locking the door this time and went to playing video games and listening to loud music for the next few hours.
It got around 5pm when I got a text message, I looked down at it to see it was from Mandy. My hands went stiff as I dropped the controller on the floor. I slowly moved my hand over and picked up the phone, preparing to read Mandy's outraged response to what happened earlier, or expecting her blackmail to begin, wondering how much money she would force me to give her. I opened my phone and to my surprise it was a simple text that said "Dinner is ready."
I breathed a sigh of relief as I got up and opened my door, even seeing my finished laundry laying in the basket next to my door, most likely put there by my mother. I put the basket in my room and went downstairs to the kitchen, seeing my mom, my step dad, and Mandy all getting food on their plates, and Mandy was wearing a sexy blue dress with her tits hanging out of the sides a bit.
My emotions were at odds with each other. My heart was pounding out of fear, but my cock was struggling to stay flaccid as I walked over and picked up my plate. I sat down with my food and ate, sitting right next to Mandy as my mom reminded me of their summer trip the next day.
"So we'll be leaving tomorrow morning and we won't be back until next week, in that time we don't want any guests over unless you ask us first, do you understand?"
Both me and Mandy nodded our heads in agreement as we continued to eat and make small chat. I almost flat out asked if I could come with them on the trip just to avoid spending an entire awkward week around the house with Mandy, but I knew they would say "No" since they were mad at me for not picking to go to college. Mandy wasn't allowed to go either since she had no job and instead just sat around the house doing nothing, but as a total daddy's girl she never really got punished a lot. I finished my food quickly, putting my dishes in the sink and sprinting back upstairs to my room to go to sleep.
That night however I could hardly even blink, let alone close my eyes long enough for me to get some sleep. I stayed up playing video games and keeping an eye on my phone for any other texts from Mandy signaling my forthcoming doom, however nothing came. At around 2am I finally started to feel sleepy, so I laid down and closed my eyes, counting sheep until I drifted off into a nice slumber.
All through the night my brain replayed the scene of Mandy coming into my room, quickly turning it into a nightmare as she pointed and laughed, mocking the size of my cock, while was a pretty good size, but my worried mind was expecting the worst to happen. Over and over a different horrible scenario played out. One where our parents caught me as well, with her dad throwing me out the window, another where she took a picture of me and posted it online, and another which calmed me a bit as she seductively walked over and actually started jerking me off.
This final fantasy seemed to keep me calm all throughout the night, as I woke up the next morning I felt my leg being covered in my cum. I opened my eyes wide and climbed out of bed, wiping up the mess with a napkin as I heard my mom call from downstairs. I got dressed and went down to see her and my step dad getting their bags into the car to leave. As I was helping them, Mandy walked downstairs announcing "Alright well, I'm going to the gym... you two have fun on your trip!"
She hugged our parents goodbye before getting into her car and driving off to go to the gym while I finished getting them packed and ready to go. Once the car was full I hugged them goodbye as my mom gave me one last warning.
"And remember, NO GUESTS UNLESS WE SAY! We've asked some of the neighbors to keep an eye on you two while we're gone as well" She said.
"Don't worry mom, we'll be fine. You two have a good trip" I replied as she got into the car.
I gave them one last wave goodbye as they pulled out of the driveway and down the street. Once they were out of sight I went back into the house and promptly put my face in my hands and screamed.
"FUUUUUUUUCK! THIS WEEK IS GONNA BE TORTUUUUURE!" I yelled.
I went into the kitchen and gathered up a ton of food and snacks. Bread for sandwiches, chips, and a few other things before I ran upstairs to my room and locked the door. I planned on staying in my room as much as possible to avoid Mandy until our parents were back. A few hours passed by as I heard the front door open and shut, Mandy was home. I paused the movie I was watching and listened to her footsteps coming up the stairs. I looked underneath my door to see her shadow move in front of it. She stopped for a second right in front of my door for a few seconds, almost like she was listening for me before she continued past to her room.
This confused me as I turned down the volume to my TV and continued the movie. It got around 3pm when I heard Mandy yell my name down the hall. I slowly climbed off my bed and stepped out into the hallway, turning to see her bedroom door cracked open. I took a deep breath and walked down the hall, stepping inside to see her standing in front of her mirror.
"What is it?" I asked.
"Hey... I wanted to ask you a favor..." She replied
"What's that?"
"Do you mind if I use your car to go to the mall really quick? I forgot to fill mine up after I got done at the gym.."
"Why do you need to go to the mall?" I asked.
"Well I bought these jeans from there, but they seem to be a bit too tight... don't you think?" She said as she pulled on the jeans she was wearing, making them squeeze her ass cheeks tight.
"C'mon Step bro... I'll owe you one..." She said.
