We must bring the three-dimensionality of our being to the topic of masturbation as well. While it is physical, it also connects with our psyche and is a spiritual act.
In truth, every single act of masturbation is an act of worship. The question that remains is, Who is being worshiped? Who is being glorified through this act? Is it glorifying God or is it glorifying the enemy? It is impossible to engage in masturbation and not have it connect to the spiritual realm.
Therefore, guard your heart! And whatever your decision, be fully convinced; engage or not engage from a position of faith, to the glory of God, giving thanks (Romans 14:5-6, 23).