My older sister took care of me a lot, because our Mom was sick and Dad was in the Army. We played and wrestled like siblings do, but nothing sexual, until she broke up with her steady bf. I was comforting her when all of a sudden she kissed me on the mouth with tongue and all. I could feel her boobs against me and she was so passionate, I got so hard in my pants it hurt. We made out for maybe five minutes, even groping each other some. Then she pulled away slowly, smiled a weak smile, said "Thank you," and went into her room and closed the door. She never mentioned it again. Go figure.