My step-sister joins me in watching porn as she is envious of my wife

I was lounging on the couch, scrolling through my phone when my stepsister joined me. She noticed a porn video on my screen and her eyes lit up with envy as she saw my wife being fucked by a big cock. I couldn't resist teasing her about it and before I knew it, we were both watching the video together. The sight of my stepsister's tight 18-year-old body and blonde hair made me hard. I couldn't help but imagine my wife being fucked by that big cock. The thought of my stepsister getting creampied by it only made my desire grow stronger. I couldn't resist the urge to touch myself and soon found myself lost in the pleasure of masturbation. My stepsister joined in, her fingers exploring her own body as we both lost ourselves in the world of porn.