When I was 15 I learned what fun masturbation can be. I grew up in a fairly open and loose sexual environment. My mom often did not wear clothes around the house. My parents would also openly excuse themselves to go have sex. I was an only child. I guess this experience desensitized me to sex. They told me it was okay to ask questions and to masturbate, but I never did.
Then one summer my dad got assigned to go overseas on business for a month and my mom decided to go along. They arranged for me to spend that month with my uncle and aunt(mom's sister), and my cousin (17).
After being there a few days I noticed that they became more comfortible with having me there. It was really apparent when my aunt came in one morning to see if I wanted breakfast and she was only wearing a pair of cotton panties. I guess I looked shocked because she covered herself and said she thought I wouldn't mind since my mom was the same way. I told her it was fine, but I just wasn't expecting it. She then told me I could be myself and act like I would at home, she said that they often do not wear clothes.
I got up and went in for breakfast. I was wearing a t-shirt and some sweat shorts, but when I got to the table my mouth dropped seing my 17 year old cousin sitting there naked. She was beautiful - had small but perk breasts with pointed nipples and a nice trimmed blonde bush. After breakfast the fun began.
My cousin came to my room and said 'you liked what you saw at breakfast didn't you?' I told her that she was beautiful and that I had never seen a girl other than my mom naked. She was suprised and sat down on the bed. Then she asked 'you masturbate don't you?' I told her that I never had.
She said that she was suprised and told me that she was going to change that. She told me I was missing out on the best thing in life. She leaned back on the bed and began rubbing her breasts. She invited me to get naked and join her. I watched her some more and then got in the bed, but did not strip. she continued to pleasure herself and my cock got rock hard. For the first time seeing a naked girl was getting me hard. She then said she told me to get naked and rolled over and tugged on my shorts. I helped her pull them down.
She told me that I had a nice cock, and that I didn't need to be ashamed. She told me to stroke it. I was hesitant as I never had done it before. After several urgings I finally did it. It felt great. She continued to rub herself. After a few minutes I felt the tingling and stopped. She asked why and I told her what I was feeling, she said that I needed to continue that it would start feeling better. She reeched over and grabbed my hand and began guding my hand up and down my hard cock. Finally it happened, my first orgasm. I shot cum all over the bed and our hands. Shortly after that she cummed from the excitement of the situation.
She helped me clean up and told me that I needed to make this a daily habit. I told her no problem. For the rest of the month we sat around and masturbated for and with each other. A couple of times her mom and dad would join in stating they needed to show us how adults do it.
To this day whenever I get to visit them we sit around and masturbate. Nothing more ever goes on and we respect that. I am now married, my wife and I are open and when we visit my family we keep that openess. We plan on raising our children in the same open environment.