If you are female and dream that you see or are a boy, then it indicates that you are developing the masculine aspects of character. Alternatively, it may represent your feelings about a real-life boy who is important and significant to you. You may have a crush on this boy and your waking thoughts of him has carried over into the dream world. Your motherly instincts may be taking over.
If you are an adult male and dream that you see or are a boy, then it suggests your playful, innocent, childlike nature. Alternatively, it can symbolise the immature aspects of yourself that still needs to grow. Your inner child may be trying to draw your attention to parts of yourself that you need to recognize and acknowledge.