Prim and Proper

My sister Beth 23 has always been little miss Prim and Proper as far as I concerned. I'm Alex 27 and growing up Beth was the perfect child never getting to trouble, unlike me never out of trouble. Our mother died when I was 9 and Beth was almost 5, she had cancer. Our father John never remarried and looked after us well, but I was a big concern for him. They were in their thirties when I was born and born were doing very well in their careers. I didn't do well at school and left at 15 and became a plumber and was working my own small plumbing business when my John died of a heart attack. We were both left fairly well off from his estate. Beth was at the local university and I ran my plumbing business. Beth wasn't the party girl and would rather study than party. I enjoyed a drink after work and dated some as well nothing serious. With John's death I used my inheritance to buy a house with a large shed on the same block, I done up the house. Beth moved in with me as the apartment John owned was sold off, for the first several months you wouldn't know she was there as she is so quiet. Beth and me always got on fairly well. The death of John hit her hard and I made sure to keep her company as much as I could. As far as I know we have no other relatives, John had never mention any to me. Beth would go to the university and I would work my business, then Beth was hurt in a fall on the steps of the university. I was called and visited her in the hospital, some idiots were playing with a football and 1 had bumped into her on the steps knocking her down the stone steps. She was in hospital for 2 nights and was laid up for for 5 days. With her confined to her bed for several days at home, I would drop in during work hours to check on her. She kept up with her studies online, when she was up and about again I took her out for dinner on a Friday night. This became a regular thing for us and seeing a movie after our dinner. While watching a movie, she said it was cold in theatre and I put my arm around her and she cuddled up to me. Cuddling continued from then on and even when we were home. Then one evening I kissed her and she kissed me back. It became a very passionate kiss and I started to fondle her, she didn't try to stop me and we ended up fucking in my bed. The next morning we continued fucking and she moved into my bed with me every night since then. Beth continued doing her courses at university and is now 8 months pregnant. She wears our late mother's rings and we pretend to be married.