I walk in on you trying to hide the fact you were wanking off in your bed, is that why you spend so much time in here? I grab your laptop to see what you were watching but can only see pictures of our step-mom. After some teasing, I come to realise we have something more in common than I thought. I fantasise about step-mom too, lying in the room next to you, fingering my pussy in bed, thinking about all the dirty things I'd want to do with her. Now your own step-sister is sitting on your bed talking about all the fantasies she has about your step-mom, while fingering her pussy. How fucking naughty does this feel, jerking off together, just wanting your step-mom to find you both and join in.