My stepdad never really got along. He was an opinionated asshole, and I was a stubborn kid. We had a family reunion one year where he brought his little sister. I got it in my mind that I was going to really show him this time. She was a bit younger than me and impressionable. I hung out with her the whole day. We were both drinking playing little jokes and messing with one another. Eventually I worked up the courage to say I was horny. She seemed a bit apprehensive at first I could tell she was turning the idea over in her mind. I asked her what was wrong and she said I want something. I asked her what she wanted, which she replied, you. Before I knew it she had my pants off and was sucking me off. I eventually bent her over a bench by the lake we were at and fucked here till we both came. We laid there naked for a while. It hasn’t happened again and we never told anyone.