Horny boy destroys his older step sisters ass from behind

Blonde older step-sister thought I was her boyfriend. I got from school very horny; I decided I wanted to watch porn, but my phone's battery was low, so I decided to walk up to my step sister's room to borrow her charger on getting there, I run into her sleeping with only her panties on which got me hard. I decided to stick my hard dick in her ass; while I was fucking her from behind, she thought it was her boyfriend but later realized it was me.