Tricked Him

One day there was a 14 year old girl in a nice short skirt. A boy about 16 walked up to her and said, "I bet you can’t climb that tree".
The girl replied, "Oh yes I can, watch".
The girl climbed up the tree and the boy looked up her skirt. When she came down he said, "I like your knickers".
The girl got upset and told her mum her mum said, "You silly girl you let him look up your skirt to see your knickers".
The next day the girl wore an even shorter skirt the boy said to her again, "I bet you can’t climb that tree", pointing to a taller one.
The girl climbed it and when she came down the boy never said nothing, he just looked very happy.
The girl told her mum again her mum said, "You silly girl you showed him your knickers again".
The girl replied, "No I tricked him this time, I didn’t wear any ".