We unlocked the front door, got naked and jumped into my parents bed. When we heard the front door open we yelled that we were upstairs in bed. He b...unded up the stairs, found us naked and started to strip. We jumped up and helped remove his clothes.Once he was naked, we sat him on the bed and said that we had to have a serious conversation. First, I said that I had a a secret that he had to help us keep and second, I needed a huge favor. Since almost any horny, naked, teenage male who is. After dinner, she took the rest of her things to the guest room and said she was going to call it a night. "Good night sis" I called out watching her sexy ass sway as she walked away. Life had been good to my baby sister she had grown into quite a sexy woman. That night I dreamt that we made hot passionate love on my bed, where we kissed and touched each other all over. I masturbated in bed that night, hoping I’d get a chance to see some skin or get some type of action soon. Little did I know. It was something that had made her uncomfortable to wear even though she trusted Jeff's skills in rigging. Thoughts of strangling without being able to let Jeff know unsettled her. However, like everything else since she agreed to become part of this fantasy, she had very little control over it.The rope loosened and fell away from her neck and the Oriental girl felt her long, black hair being lifted up and something else being put around her neck. A collar, she imagined as it tightened around. ...good....er....no, I mean you look gorgeous"I looked at dad and we were both dying of embarrassment. I flapped my arms in the air in a resigned gesture of being caught and said well I might as well give you a twirl.I slowly spun round wiggling my ass like I had practiced many times in front of the mirror.Dad nodded slowly and then I couldn't believe what I saw the towel round my dads waist was slowly being pushed out by something growing and growing very big.I simply stared at this growing.