The Submissive Crush
The romantic crush is a sudden falling in love. You think about the person you love, you want to be with him, you look eagerly for any clue that he like or does not like you. It feels wonderful and it is full of anguish. You probably fantasize about pleasing him. Males can have fantasies of sacrificing themselves for their loved one. Note how much this is like submissiveness.
Anyway, submissiveness somehow triggers this same state. You should watch for this. When it occurs, his submissiveness isn't a game any more, it is for real. He will crave your attention, and he will be sensitive to disapproval.
The submissive is looking for the "tie that binds". Sometimes it is literally a rope, sometimes it is some other submissive fantasy. But the ultimate control, and the natural control, is his love for you.