Step sister catches step brother (me) masturbating in midnight at my room and she is shocked after seeing my thick cum

I am very horny person I love sex and I am watching porn in midnight and masturbating in my room and imagine about my girlfriend my girlfriend is so hot she had big boobs curvy body 36 29 38 she has very big ass and pink pussy whenever I think about her I will get boner automatically because she is so hot and sexy I am very glad to have a girlfriend like her she is so hot and I am masturbating in my room at midnight then my sister suddenly come to my room and catches me masturbating and seeing my hide load of sperm.