Owning my sister

I and my sister lost our parents in a car crash in 2015 and I was at university at the time and my sister was working in a dress shop. She didn't study and partied instead of studying, because of the accident we shared the estate, and I kept mine and invested it and on leaving university I got a great job. When the pandemic struck, I was sitting pretty as they say. I had my own home and could work from home as well. My sister had blown thru her inheritance and was relying on her job which disappeared shortly after pandemic started and she was soon in trouble. Unable to pay her rent or pay for anything, so she turned to me for help. Of course, I took her in and would provide for her. Her stay was only going to be until the pandemic was over, but it dragged on and on. Even I was starting to get stir crazy, but my sister became desperate. Before the pandemic she partied and fucked regularly and now she was living like a nun. I'm no Adonis far from it in fact and I started to look very good to my sex starved sister. Not that I realized at the time, I was still a virgin and rarely masturbated. But one night my sister joined me in my bed, and she was totally naked. She wanted sex and I was the only man available so was going to fuck her brother. I was shocked at the time is quite correct, but unwilling I wasn't. I let have her way with me as the saying goes, once we had started it became very regular for us to fuck. Always her taking the lead, but I'm no push over and over time I started to assert myself. It was fairly simple not engaging in sex when she wanted too, then insisting on sex when I wanted too. Overtime I became more dominate in our lovemaking. After lockdown was over, I was in control, and she was my willing sex slave you could say. But she was also late with her period and then miss another and finally getting tested was confirmed as pregnant. You didn't need a high IQ to guess who the father was, more test followed and with everything fine we decided to have the baby. She was planning on having the baby and after it was weened, she would leave it with me and restart her life. But she became very attached to the baby girl we had and changed her mind and as of last week is pregnant again. Yes, I'm the father again and we share my bed every night, just like a married couple. My sister has given up her previous life and is content living with and our daughter. But there's always a chance that she may leave in the future. But that is only a maybe at the moment and at the moment I have a very willy sister.