When I was about 20 years old I heard my parents having sex - quite wild, loud sex. They thought I'd gone to bed, I had a terrible headache earlier - but as I'm getting up to get water I hear a very loud moan..followed by a spank. "You like that huh? like that fucking cock in your ass!?" my dad roars, followed by a series of smacks. Hearing my mom close to orgasm moaning "fuck my ass baby.." will never leave my mind. I panicked at first - but after gathering myself a few moments decided to listen in more - as I hear the smacking picking up pace, and then the roar of my dad cumming. "All..over..my..face.." my mom moans. I sneak back to my room...and masturbated to the vision of that happening in my head.