In the dance world, everyone is constantly in contact with each other: owners, instructors, students, parents, artistic directors, competition owners, master instructors, etc. The industry is amazingly small, and reputations often precede personalized introductions.
With the industry, including the everyday workplace, being so small, it is imperative that professional boundaries are maintained while still treating clients and associates in a personalized manner.
When boundaries are broken, conflicts can arise and careers/relationships can be jeopardized. Plus, it makes it difficult to be objective in your opinions because emotions affect perspective.
Apply the rules to everyone, and make exceptions for no one (or everyone).
You will find that your everyday operations will be smoother and you will receive a heightened respect on micro and macro levels.