Sister In Law

I have fancied my sister in law ever since I met her when I started going out with my now wife. Never acted on it because I was not sure if she would reject me and tell her sister but a few days ago she was at our house and I was erect as I usually am when I see her. She must have noticed it and said jokingly was it something in my pocket or was I pleased to see her. I said she should check. She grabbed it and told me to pop round sometime. I waited a couple of days and rang her to ask if it was ok to visit. She said yes. I was so nervous but very excited. When I got there she was in her nightwear. We kissed and went upstairs to her bedroom. It was amazing. The best sex I have ever had. She didn't want me to wear a condom because she wanted my cum inside her. We have arranged to meet again.