I'm lucky to be in D/S relationships with several men (they all know each other) who enjoy the respect and obedient servitude that I do, only from the other side. I worship big cocks and I love to get fucked, but I'm not a masochist. There is also an aspect of dom/sub that isn't based on pain or cruelty instead it's based on respectful obedience and service with both top and bottom taking pleasure from the other. If the bottom is a masochist that works out.
It tends toward the self centered and selfish.
When people think of dom/sub relationships or scenes they usually think of the leather scene, which is sadism/masochism.