Summer Fun

When I was a teen I spent time at and with some of the neighborhood kids. It was summer so everyone was home alone for most of the day alone. The neighbors had a pool, they were brother and sister. One my age and the other 1yr younger. We were all swimming and the girl proposed truth or dare but we agreed all dare only.
Not long before we were daring for bathing suits to come off. I dared my friend to to stand in front of us with his shorts down. Being young we weren't very big in the penis department yet. Next he made his sister pull down her top for us and she did. I knew my turn was coming and was rock hard. So pulled down my pants to reveal my boner. We ended up swimming around a couple hours naked. It was great gun that we ended up doing all summer