After a few minutes of looking at a domme slapping a sub's balls I was rubbing my cock. Tim could see me but coyly kept his eyes on the tv. I moaned... to turn him on more which did get his attention from the tv. I kept this up but, it was getting uncomfortable with an erection in my jeans even though I'm very small cocked. It was a poker game to see who called who's bluff and initiated the first gay move. I figured I'd tease the ante up a little and said my erection was getting awfully. Married to Chris with 2 grown up k**s, all in all a lovely family set up. Every now and we have a works night out, a meal few drinks that kind of thing. As she lives close to me I volunteered to be the designated driver. I picked her up and off we went, meal was ok and as I'm a people watcher I enjoyed seeing everyone let their hair down. Mandy was enjoying herself, maybe had a few too many drinks, but she looked happy.So it came time go we walked to the car and she linked her arm through mine.. As the story went on, I started to get aroused. I shifted a little to free up my growing member.I looked over at my sister and watched as she read the text. I scanned down and could see her nipples, visibly erect under her shirt.That only contributed to my own growth.When the story was finished I went back to the main page. We scrolled down the page when my sister said, “Here, read this on, it’s one ofmy favorites.”I looked at the story. It was about a brother and sister having sex on a trip. ” So I stopped and she started jacking me off again. She looked at my face and saw it was turning red so she told me, "don’t cum in me."“I'm not going to.” She started moving her hips back and forth and jacking me at the same time. I was rubbing her clit and I could feel her tighting up again and then I felt it a little pop. I looked down and saw I was a little deeper in her. I looked at her eyes which were smashed shut with more tears coming out. I asked, “do you want me to stop?”She replied,.