Fucking to share the secret

My stepsister always walks around the house and tans naked when the parents aren`t home and this time I decided to film her ass to showcase my buddies at the gym. When she caught me stagging on her I tried to make it look like an accident, but my hardon totally gave me away. I thought she`d tell on me, but she preferred to just fuck me and share the secret. If only I knew my stepsis was such a slut with a cock-hungry hatch and a taut pussy! Now I know!