My brother (29m) and I (24f) often go to my parents' house because our mom really values family and always brings everyone together. So at night, my brother would often sneak into my bedroom, get into bed behind me, and then quietly fuck me while my parents slept in the next room. We both realized that it was dangerous and we could be found out, but I never tried to stop my brother from inserting his cock into me.

We had already done it a few times, but one night we were too careless and loud and we heard a knock on the door that opened. We stopped fucking immediately, but my brother didn't take his cock out of my wet pussy and we both stayed lying still.

My mom came in, turned on the light, and saw my brother lying in bed behind me, but the blanket covered the lower half of our bodies. We both pretended to wake up and she asked why he was lying there. My brother replied that he couldn't sleep in his room because it was cool and the heating wasn't on yet.
Mom said something like she would buy heaters tomorrow and that from now on we would only sleep in our rooms. He nodded, but all the time his hard cock was deep inside me. When my mom left the room, we continued to fuck, although I was very nervous and afraid that my mom had found out about our relationship. This time we did it much slower and quieter.