At first they would use a slender finger that they would tentatively slide into their tight little hole. But as the excitement started to build and the juices flowed freely, the well lubricated walls of her vagina would expand. It would soon become apparent to her that a slender finger was not going to be enough to satisfy her. So she tried inserting two or three fingers at a time, this was better but still not 'cutting the mustard'. With a bit more experimenting, it didn't take long before her whole fist was stuffed up her no longer tight little pussy. Now she was finding this new discovery so pleasurable she would practice it at every opportunity. Initially she felt guilty, because nice well brought up girls were not supposed to touch themselves. But the more she did it the braver she became. She and her friends would get into a huddle and whisper to each other just what they had discovered.