hazel, my first thought was that 13 is considered the age of accountability which you probably know is when a teenager is considered old enough to think like an adult and make up their own mind. the term is used in reference to deciding what one thinks about God but i think it could be about anyone and probably about an authority figure in your life. you are fooling around with this kid so maybe there is a part of you that feels you "should" (the cops) be more grown up and not acting like a young teenager. you feel like you are not acting your age. you think you are doing something wrong and are going to get in big trouble for this.

just know that pretty much everything is symbolic in dreams so it's definitely not about the literal meaning of what was happening.