They sounded like moaning. I thought she might be ill. I reached for the door knob and then heard what sounded like her bed rocking back and forth. Which would make sense if she was sick. So I opened the door. There before my eyes were my two kids, naked as jaybirds. Bart was on top of Lisa and his stiff dick was buried deep in her ass. My son was fucking my daughter in the ass! And she was enjoying it. She moaned each time his long, hard cock pressed down in to her rectum. Neither paid any attention to my being there until I screamed in shock. They both looked up at me and rolled over on the bed. Bart tried to shield his naked body from me with his sister’s equally naked body. But all it did was give me a different view of his cock sliding between his sister’s buttcheeks and deep into her ass. He tried to hide from me but didn’t stop fucking his sister. Lisa didn’t know what to do. She was ashamed that I had caught them but was obviously deep in lust from the feeling coming from her ass. She just moaned louder as Bart’s hands came around to cup her tiny pre-teen breasts. His fingers gently pinching her stiff nipples. “Bart! No! She’s your sister! “Just at that moment, Bart rammed deep into his sister’s asshole and began to convulse in orgasm. Lisa moaned very loudly and it was obvious he was shooting a big load of hot cum in to her butt. …to be continued!