This dream may symbolize a desire for excitement and spontaneity in your life. The shower represents a place of cleansing and renewal, suggesting that you may be seeking a fresh start or a release from stress and responsibilities. The presence of your little brother’s half brother, who you have no relation to, could represent a new and unfamiliar aspect of yourself or a new person entering your life. The fact that he is 20 years old may symbolize maturity and experience. The mirror could represent self-reflection and introspection, while the glass shower door could symbolize barriers or boundaries. The physical intimacy and arousal in the dream may suggest a need for passion and connection in your waking life. The repetition of showering together could indicate a desire for a deeper emotional connection with this person. Overall, this dream may be a reflection of your subconscious desires and needs for excitement, intimacy, and connection.