Step sister catches step brother masturbating in her bedroom

I am watching porn videos at midnight in my sister bedroom because she is gone out with her friends so I went to my step sister room and started watching step sister porn videos and started masturbating and imagine my step sister because I love my step sister and I want to fuck her because I have once seen her on bathroom she is so hot ? she have big ass big boobs and very beautiful nice pink pussy I love that and then I decided one day I will fuck her and now I am waiting for that day to fuck her then when I was masturbating in night in her room she suddenly came back to home and catch me during masturbating and get shocked after seeing my big dick.