This dream may symbolize unresolved feelings and conflicts with your ex-guy best friend. The school assembly represents a gathering of different aspects of your life, and the presence of your ex-guy best friend suggests that he still holds a significant place in your thoughts. The betrayal you experienced in the past is still affecting you, as shown by his sudden appearance and the fact that he showed you his private parts. This may represent a desire for revenge or a need to confront him about his actions. The girl from school who joined him in the sexual act may represent your feelings of jealousy and insecurity. The fact that he kept looking at you during the act suggests that he wants to gauge your reaction and possibly make you jealous. The encounter in the bathroom may symbolize a desire for intimacy and a longing for the past, but the fact that you were pushed against the wall may also represent a feeling of being trapped or controlled. Overall, this dream may be a reflection of your unresolved feelings towards your ex-guy best friend and the need to confront and move on from the betrayal.