My stepmom surprised me while I was having sex with my curvy stepsister

I was in my room with my stepsister, a curvy and fat girl, when she suddenly started to suck my dick. I was surprised and excited because it was my stepmom who had come to see her daughter, but little did I know, she had come to surprise me too. As I continued to fuck her, my stepmom walked in and caught us in the act. I was shocked and embarrassed, but my stepmom just laughed and told me not to worry, that she didn't mind what we were doing. She even joined in and fucked her daughter while I watched. It was a strange feeling, but also very exciting. I had never seen my stepmom get so wild before. It was a strange and unexpected situation, but one that I will never forget.