My stepsister's boyfriend did not suspect that he would wake up a cuckold!

Recently, I witnessed the quarrels of my stepsis and her boyfriend involuntarily, but this very day surpassed all the previous ones. My stepsister's boyfriend came home tired as hell and angry as well, he just wanted to sleep, but my stepsis demanded attention. She walked in front of him almost with no clothes on, trying to seduce him with her sexy body. She wanted to appease him, but he just turned away and fell asleep... I went to their room to show her some support, because she was very upset... I hugged her a bit and immediately felt a wave of her unbridled sexual energy dragging me in. Obviously, we could not keep this under control, and after a moment, my cock was deep inside my sister. I began to fuck her right with her boyfriend sleeping nearby... But later on, the worst thing happened - he woke up...