(M)y best friends sister
Me and my best friend have known each other since we were about 5 years old. His sister was a couple years older than us, and let me tell you, she definitely got the good genes in the family..
The first time this happened I was 18 and she was 22. I was getting ready to go play D1 baseball, and about a week before I left, my family threw me a going away party. All of my friends came (including my best friends sister). About 2-3 hours in, everyone was outside playing corn hole, and just hanging. I had to pee, so I went inside to use the bathroom, and didn’t even think anything like this was about to happen. I was walking through the kitchen, and my friends sister was getting something to drink. As I walked by she looked me up and down and gave me one of those fuck me smirks, but again I didn’t think anything of it. I got in the bathroom and started doing my thing, and the next thing I know the door flies open and she’s just standing there. I freaked the fuck out at first and asked her what the fuck she was doing. She walked in and closed the door behind her.