My Brother's Keeper

My father Graham died in a traffic accident 2017 and my brother David was badly injured and had brain damage. It wasn't major we were told at the time, I was just going to university and so my mother Wendy 47 had to take care of David. David 24 was always good at working with his hands making things out of wood. That wasn't affected by his accident, at university I done well and finished near the top of that year. I'm Emma 28 got a good job close to home, to help Wendy with David. David became quite reclusive after his accident and worked from home, but there was one thing the doctor either missed or didn't take into account David had lost his inhibition when it came to sex. At first it wasn't a problem as he was like hermit, rarely taking to Wendy or me. But he became sexually aroused around first Wendy and later me, which caused problems at first. Mainly Wendy finally just gave in and became his lover. She never worn panties in the house and slept naked. When David got horny he would go to Wendy and she would let him fuck her. She was lucky she had her tubes tied before the car accident as she and my father decided no more than 2 children. So getting pregnant wasn't a concern for her, I found out about it on a break from university and Wendy told me not to try and do anything about it. David was a good lover as she had trained him she said and she enjoyed the sex. So it wasn't forced on her and she was very willing I let it be. On my return home David kept his distance from me. Then Wendy got ill and went into hospital for a week, while she was in the hospital. I was looking after David and he became less hesitant around me. Then one night he joined me in my bed and to save a fuss and being curious of our good a lover he let him fuck me, I thought one wouldn't hurt. He fucked me 3 times and the rest of the time Wendy was in hospital 3 days I was used by David for sex. I wasn't in any relationship, nor getting any sex and had been masturbating myself and on protection. So I like the servicing David was giving me, not that any of us are something special we're just average. I thought my mother really knew how to train David and done a very good job doing it. I didn't have to tell Wendy that David also using me for sex she could see it on getting home how he was really close to me instead of across the room. Which was handy she said as she was still recovering, but a week later she was being fuck again and we started having threesomes. A friend at work got pregnant and I got a bit clucky Wendy called and I stopped taking precautions, So now I'm pregnant to David and the baby is fine. I had done investigations into what would happen if we reported David's loss of inhibitions. It seem cruel to me chemical castration first, followed by actual castration and drug control along with and the person became more a vegetable than a person. I decided I was more willing to be fucked by David then have him destroyed. He is my brother and lover now and as long as he wants to be.