The next morning, I woke up early before my parents and decided to go for a run. After all, I needed to get some exercise after that intense night of gaming. When I got back, I noticed my dad was already awake. He asked me how my run went. "Good," I said. "I needed it after last night." My dad laughed and then told me he had something to show me. We walked down the hall to my sister's room. She was barely awake, so we quietly opened the door and tiptoed inside. As soon as we entered, I saw my sister resting on her bed, completely naked except for her mother's one-piece bathing suit, which she was wearing like a thong. Her ass cheeks were exposed, and I could see them clearly from where we stood at the foot of her bed. My dad looked at me and winked. "You like what you see?" he asked, grinning wickedly. I nodded, unable to take my eyes off my sister's perfect ass. Then, without warning, my dad leaned forward and began to lick her asshole! It was clear that he wanted to taste every inch of my sister's body, and I couldn't believe what I was seeing. My heart raced as I watched him pleasure himself with my sister's tight hole. After a few minutes of licking, my dad sat down on the edge of the bed and pulled out his hard cock. He motioned for me to come closer, and when I did, he instructed me to kneel between his legs. With my hands wrapped around his thick shaft, I began to stroke it slowly as my dad continued to lick my sister's ass. As I stroked his cock, my dad reached over and grabbed a handful of my sister's hair. He yanked her head towards him, putting her tongue into his mouth. They started making out passionately, their tongues intertwining as they explored each other's mouths. Meanwhile, my hand was working furiously on my dad's cock. I felt it throbbing in my grip, growing thicker and harder by the second. Finally, when it was fully erect, I let go and stepped away. My dad stood up and bent over my sister's prone body. He placed the tip of his cock at the entrance to her pussy, then pushed forward until he was balls deep inside her. My sister moaned loudly as my dad thrust into her again and again. He held onto her hips tightly, pumping his cock in and out of her wetness. I watched as my sister's body rocked back and forth beneath him, her ass cheeks jiggling with each thrust. Finally, my dad gave a loud groan and came on my sister's ass. He quickly and turned to face me. "Now it's your turn," he said, smiling broadly. "Lick your sister clean." I didn't hesitate; I knelt down and started eating my sister's ass while she moaned with pleasure. When I finally finished cleaning her up, my dad patted me on the back and said, "That was great, son. You did well. Now let's get ready for breakfast." We left the room together, both of us feeling satisfied and happy. And as we walked back down the hall, I couldn't help but smile knowing that I was a kinky son and brother.