Second meeting with my sister almost got us caught

Several days passed after the first encounter with my sister, and we didn't talk until everything ended. But one afternoon when our parents left, my sister called me to her room, I didn't know if I should go but due to my sister's insistence, I went. My sister was sitting on her bed, told me to come in and close the door, so I did. She started telling me that what we had done was wrong and she didn't know who else to talk about it with. I said it couldn't be helped. My sister said it couldn't happen again, that it couldn't pass while talking. While she spoke, I took the opportunity to kiss her at first, but then she pushed me away, making me fall off the bed. She got angry and said it couldn't happen again. There was a silence, and my sister got on top of me without saying anything. She started kissing me, so I started touching her body. My sister put her hands under my shirt, and I helped her take it off. She kissed me with passion, and I started moving my hands up to her back, trying to unbutton her blouse. My sister took it off, leaving us in a state of undress. She told me it was better if we got into bed. I agreed and sat on the bed. My sister got on top of me again, and we kept kissing with my hands searching for the button of her pants. My sister noticed and stood up to take them off herself, but then came back and got on top of me again. With my hands under her clothes, I felt her skin. She told me to help her unbutton my pants because her hands were trembling and she couldn't do it. I helped not only with the button but also took off my pants, leaving me in my boxers. I put my sister underneath me and started kissing her neck, feeling her breasts and hard nipples with my hands. My sister put her hand under my boxers, squeezing my buttocks slowly lowering my underwear making my penis I would start appearing above my boxers, help my sister and take off her underwear and with movements of my legs let them fall somewhere on the bed I started rubbing my penis against my sister's vagina over her underwear leaving some liquid stains But I had a lot of excitement from doing it again with my sister I put her on top of me to lower her panties so that we could both be naked but when we changed positions, my sister got up on her knees and alone took off her underwear and told me now she would have control with her hand guiding my penis into her vagina until she put it in the entrance and slowly started putting it in I started twisting because it felt so good to be squeezed by her thighs and pulling my sister towards me for my penis to enter fully my sister started moving forward and backward I meanwhile played with her breasts and buttocks my sister was kissing me but kept getting back on her knees to keep moving a little clumsily but she felt very well But we heard someone opening the house door, it were our parents who had arrived very quickly my sister jumped off the bed and I sat down looking for my clothes found my boxers and left the room quickly with only my underwear on the closest thing was the bathroom because my room was farther away I ran into my mom who told me to respect that my sister was also in the house I smiled remembering we used to do it when we were alone but between the bathroom and I told my mom I wouldn't go back Hours later, I talked to my sister who told me we almost got caught and had to be more careful I told her when we finished what we started my sister with more confidence told me that when our parents left for days like they always do.