Dreams involving past relationships or significant figures from our lives, like a deceased parent, can be quite powerful and often reflect our inner thoughts and feelings. In your dream, the one night stand defending you in front of your dead father might symbolize a few things:

1. Desire for Approval: This could indicate a longing for validation or approval from your father, even in his absence. The presence of your one night stand defending you suggests that you may seek support from unexpected places or individuals.
2. Conflict Between Relationships: The dream may represent a conflict between your past and present relationships. You might be grappling with feelings about your one night stand and how it aligns with your values or your family's expectations.
3. Processing Grief: Since your father is deceased, this dream could be a way for your subconscious to process your grief and unresolved feelings about him. The act of defending might signify a desire for reconciliation or understanding regarding your current life choices.
4. Self-Defense and Acceptance: Your one night stand defending you could symbolize your own need for self-acceptance and self-defense against judgment—either from yourself or others, including your father.

Consider reflecting on your feelings towards both your father and your one night stand. Are there unresolved issues or feelings that you need to address? This dream could be prompting you to explore those dynamics further.