When I was 16 and my sister was 17 we had sex. It was in the family camper and it was unprotected. We were both virgins until that point , and after we had a good relationship but a little strained. We would sometimes kiss pretty heavy when no one was looking. Once, when we were in our 20,s she sucked my dick in the coat room of a church. Our middle sister was getting married. She let me cum in her mouth. That was the only two time we ever hooked up.