She said if it might make me feel more comfortable why don't I come out from the table and let her see it. Maybe that might help with my embarrassment. It took a moment and I stood up and walked out in and stood in front of her. She said oh my you definitely are aroused that is for sure. As I stood there as we talked about anything to try and see if it would go down but it wasn't. She said this isn't helping is it, her sitting there looking at it huh? I said no. She said it's making it stay hard isn't it. I blushed. She said no need to blush after all I have raging hormones and she is a female. I said but she is my sister. She said yes but still a female with a naked guy with raging hormones what else was going to happen but getting an erection. She said she knew. We took more pictures but with me using various things to hide my erection.
After about another hour or so we stopped and I took away what was in front of my erection and I was still hard as can be. She said damn she thought it would have gone down by now. She said not to be funny but I must be really excited. We sat there on the couch and talked for about another 20 minutes when she said you must be very frustrated right now and probably want some relief. I said yes. She said if I wanted to I could go take care of it if I wanted to or stay there and take care of it while she watched. After all she asked if she was the one that caused it. I said she was but I couldn't believe she was willing to watch. She asked if I minded her watching. This was my half my fantasy come true. She didn't catch me masturbating but she was willing to watch. She said what's it going to hurt, her watching me. That was true. I asked her to move so I could lay down on the couch. She moved to the end of the couch. It took a moment before I wrapped my hand around my shaft and started stroking. I tried to go slow to let it last but I couldn't was way too excited and her watching and being able to see everything from where she was sitting. I mean seeing me totally naked, my balls, my erection, my hand stroking my erection. My whole body in other words. It didn't take but about 2 minutes or so and I was squirting all over my chest and stomach. When I was done she got me a towel and I cleaned up.
She said I probably should get dressed as its getting later and mom might get home soon. As I got dressed she told me that if I ever needed to and was very frustrated like this again she wouldn't mind watching me again. If I didn't mind that is.