Sister caught me
It happened so fast I did not have time to get my shorts pulled up, I had to reach out and grab her as she was caught in the fast moving river. When I pulled her towards the slower current she reached out and grabbed a hold of me and as she did she ran her hands across my hard eight inch cock. After she was safe in the slow moving water of the hot spring I let go but she did not and for about 20 seconds she still had her hand on my cock.
But let me start from the beginning, it was my freshmen year in college and our family vacation was in late September so I got home and we left for two weeks of camping in Yellowstone. Mom and Dad slept in the pop up tent trailer and Cassie and I slept in a tent it was ok because we are both very close and not an issue but that meant I really did not have a lot of privacy to masturbate.
One evening we were at Mammoth hot springs area camping and we went to the river called boiling river, when we got there the first thing I noticed was three very cute girls there and I quickly got horny. After about 45 min of watching them and thinking about how much fun it would be to be naked with them, I was really hard and since it was getting dark I floated down the spring to the very end about 100 yards from Mom and Dad and Cassie and the rest of the people. It was there that I pulled my shorts down and slowly started to masturbate.
Stroking my eight inch cock up and down running my hand across my bald balls I was really enjoying the feeling of the hot water caressing my dick as I sat there. Then I heard my Dad yell grab her and I looked up as Cassie was swept in the cold fast moving river that was right next to the hot spring. I just reached out and took a hold of her and pulled her into the warm slow moving water I yelled up that I got her and then I realized she still had not let go of my hard on. I was caught and I knew it, she asked me what I was doing I said nothing she said it does not look or feel like nothing and laughed then let go. We have always been close and we both have seen each other naked many times but this is the first time she has actually touched me and the truth was I liked it. Dad started to come down so I pulled up my shorts he said time to go and we all got out. Later that night in the tent Cassie rolled over in the tent and asked if I was masturbating I said yes she said can she watch next time? I was shocked and said why she said she wanted to see and if I let her see she would let me see. Well that was all I needed to hear and I said yes next time.
The next day we woke up and Mom and Dad said we were going to old faithful and were going to stay there tonight. We got there and Dad went to get the hotel room when he came out he gave me a key and said you and Cassie are in a room on the second floor and we are on a room on the third floor I looked at Cassie and she smiled. The whole day I noticed she kept flirting with me a lot. After dinner we all went for a walk around the boardwalk and since it gets dark early we brought our blankets. We sat and watched several geyser erupt and it was fun then Mom and Dad said they were going back I said we will be along soon hoping to see the geyser we were sitting at for the last hour to erupt. I felt Cassie snuggle closer to me and she said the words I will always remember for the rest of my life, 'will you show me your dick now' as she did she put her hand on my crotch. I said if you want you will have to wait until we get to the room. She looked around and got up and she got naked right there and said like I promised you can see me if you let me see you. I was so horny I wanted to masturbate right there but I was nervous so I just got up and wrapped her in the blanket naked and I grabbed her clothing then I started walking back to the room with her in the blanket naked.
We got back to the room with only about ten people looking at her wrapped in the blanket but they could not see anything. As soon as I opened the door she let the blanket go and walked in naked I followed her and pulled in the blanket with me and she sat there naked as I shut the door and I turned to her and I pulled my pants off along with my shirt. For the next two hours I masturbated for her and she masturbated for me and we both masturbated each other. It was the best thing that I have ever done and we ended up sleeping in the same bed naked that night.
The next morning I woke up with her snuggled up against me and I ran my hand all over her tight body and really thought about wanting to do more than just masturbate. She woke up and for the next ten minutes we just laid there touching each other. She asked me why I shave my pubic hair I told her I like it bald and enjoyed the feeling. She asked me if I liked her with hair on her pussy I said yes because it was light and not full. It was three nights later when we were camping at the campground slough creek that we actually did more than masturbate but that's for another site.