I know what you're talking about. I used to look forward to when my little sister's friends came over. two of them in particular were quite cruel, one was flat-chest tsundere all the way (I only discovered the "dere" part long after the fact, of course) the other was more of a bully, and was pretty skinny, but not quite as flat (who also, apparently, had a thing for me, which I also didn't learn until after the fact).
They both had a tendency to pester me while they were there; I made a show of being uninterested, but that was mostly for fear of them losing interest if I were to cooperate. The Tsundere girl would barge into my room, pin me under my desk, and search my computer. apparently, she really liked Ranma. When she stated watching some, I would heckle her, and she would stomp on my face to shut me up. The bully girl would often take my stuff, and when I tried to get it back, she used the opportunity to beat me up. she once ran up a tree with a game, and when I tried to get up she stepped on my fingers and knocked me off the tree. luckily I didn't land on the sidewalk, but I did hit my head when I fell.