I see what you are saying but for me the endurance of pain is not how I see myself being devoted to him. I enjoy the pain and he enjoys giving it. My greatest pleasure comes from pleasing him , which isn't just physical things. I am a masochist and enjoy the pain and the release it gives me. Enduring something for him such as pain is just a small part of our relationship and dynamic.
The love and devotion I show him everyday through my service and obedience to him gives me the greatest pleasure. Anything one does in service shows devotion not just the physical aspects.