“You give me pleasure, I give you pleasure. And to ensure an uninterrupted and secured supply of physical pleasure, you remain physically committed to me, and I remain physically committed to you. What do I want from you? Pleasure, physical pleasure. And we are committed to each other. What does this commitment now mean? You must be there when I need pleasure from you. Because our relationship is physical, we exist in each other’s lives to scratch each other’s itch, so it should not happen that one particular night I have the itch and I don’t find you by my bedside. That should not happen.”
So, the commitment practically means: “You should be there when I need your body.”
And now, what is cheating on this level? “I needed you but you were somewhere else.” And that’s cheating.