Pregnant Sister

I'm 38 the oldest of 9 children, the youngest being 19. I have 3 sisters, now 32, 27 and 24. All were married till 2 years ago when Rachel (eldest) and her husband Donald split up. He had been sleeping with his business partner Pam and had got her pregnant and when it came to light. He chose to be with Pam, Rachel wanted a large settlement and came to stay with me for a while to sort her life. As I'm the only family nearby, our mother came for a few weeks and while she was here. Rachel found out that she was also pregnant to Donald. She was unsure what to do about it, her lawyer then hit Donald with a much larger claim for the ongoing care of the child. I'm single and don't have long term relationships. Our mother told Rachel that she stay with me until after the birth or she could move back home with the family. Rachel choose to stay me mainly due to the divorce proceedings. After mother had returned home Rachel and I settled into living together, her on 1 side of the house and me on the other. She done my laundry and cook some meals and kept the house clean. About a month later on a sunday morning I laying in bed naked and started to masturbate myself. When in walked Rachel saying she had made pancakes and asking if I wanted any. On seeing what I was doing she around and left, I jumped out of bed. Got dressed and went after her saying the normal crap, like I don't do it much and sorry that I shocked her. She Replied " Relax, I do it too. Your not a freak because you masturbate. You should go back and finish doing it". I said " I think I'll have some of your pancakes first". After breakfast I helped her clear up and than she said " You go and do what you need to do now". I replied " I'm not in the mood at the moment". " Well I'm going to my room to play with myself, you can watch if you want, you can do it beside me if you want" she replied. I followed her to her room and watched her undress and lay on the bed and start to masturbate herself. Shortly after starting, she looked at me and said " Don't stand there like a statue, get undressed and lay beside at least'. So I did and while watching her play with herself, I got an erection. I just kept watching her and she said " If your not going to play with it, I will". She grabbed my cock and started to stroke it and then she started to suck it. I just couldn't hold it back any longer. I told her I was about cum and she deepthroated me taking all my cum into her mouth. After she was finished swallowing my cum, she said " Your turn, give it a good licking". Pointing to her vagina. So I did and after we showered together, later in the day. I said " Thanks I really enjoyed that and maybe we could do it again sometime". She smiled and said " I'm pregnant and won't be getting fucking for a while before and after the birth of my child. So anytime your randy I'm available, you can even fuck me if you want. If fucking your Sister and a pregnant at that doesn't put you off. I'm available it will take my mind off that ASSHOLE Donald". In the evening I said to Rachel " Would you like to sleep with me tonight". She replied " Fuck Yeah". We been sleeping together ever since, even after the baby came girl she called Susan. Donald doesn't want to have anything do with her. I have my house up for sale as I've been transferred and Rachel and Susan are going with me. I've asked Rachel would she have a baby for me and she "YES as many as you want".