The bloodline must be continued

You see, Laura and Steve, our parents told, we are a healthy wealthy family and so were our ancestors on both sides. Now we do not want to our pedigree to be interfered by inferior quality. As you are old enough now to decide for your self, we just ask you to breed with us. Yes, mum said, I can still bear children from Steve and dad can breed offspring with you, Laura. As you are both 21, you can make your own decisions. 'Mum, I never loved a woman more than I love you,' Steve exclaimed. And me, once I let my father fuck me, didn't care for other men anymore. Mum got Steve's twins and I have little Peter and another bun in the oven. Dad can't wait to see his new daughter. We'll name her after mum.