Dreams involving auditions often symbolize self-evaluation and the desire for acceptance or recognition. In your case, auditioning for a lead role may reflect your aspirations and the pressure you feel to perform in social or personal situations.

The presence of Matthew, a figure from your past with whom you have complicated feelings, indicates unresolved emotions or conflicts regarding your relationship with him. The fact that you want to stop the secret trysts suggests an inner conflict about your desires versus your need for boundaries or change.

The setting of the science classroom may symbolize a space for experimentation and discovery, perhaps indicating that you are exploring your feelings and thoughts about this relationship. It could also imply a need for clarity and understanding about your past connections.

Overall, this dream may be urging you to reflect on your current relationships, your boundaries, and how they align with your personal values. Consider what aspects of your interactions with Matthew you want to nurture or change moving forward.