It's my 21st birthday and finally time for me to learn the family secret, the step-son me and my step-sisters were born. You wake me up and chat to me about the day and spy on me while I get changed ready for my birthday. You invite me into your room, and begin to tell me my purpose, to be bred and impregnated. I strip for you nervously but do as you say, I know my step-daddy only wants what is best for me and would always keep me safe. I take your trousers off exposing your throbbing cock, getting my pussy wet for you before you put your seed inside me.