I was swimming at a friend's house across the street from me and she had some of her other friends over. It just happens that one of the girls that she's friends with I don't get along with, and she decided to be a real bitch. I was wearing a two-piece bikini where the bottoms tie on the sides. My friend went inside to answer her phone, and while she was in her house, the other girl untied my bikini bottoms while I wasn't looking. At first I thought no big deal because there weren't any guys around and it was just us girls, but when it was time to go I couldn't find them! I looked all around and asked everyone and no one knew where they were. After a while of searching, I gave up and asked if anyone had something I could wear to cover myself on the way home. No one offered anything. One of them even said, "Hey, you live right across the street, just streak on home!" My friend isn't the same clothes size as me so I couldn't borrow anything of hers, and I couldn't find anything else to wear, so in the end, I had to bite the bullet. I went through the house to the front door, looked around to see if anyone was watching, and when the time was right, I covered my front as best I could and made a dash for my house. I thought I was home free, but just as I made it to my yard, I tripped over my brother's shoe he'd left out front and fell face-first onto the ground. Just then, I heard a car horn honk and I looked up, mortified to see my neighbor's son driving by, honking, waving and smiling! He'd seen my butt at LEAST, for sure! After that, I knew I'd been spotted and I wouldn't live this humiliation down, so I just gathered myself up with as much dignity as I could muster and went into the house to cry. I was totally humiliated and the next day at school the girl who untied my bikini brought it into school to prove it had happened, then gave it to me in front of everyone and talked about getting exposure. I wanted to die!