This is very true, and it took me a long time to learn this when I started coaching.I am not your friend (or your parent's friend)...I am your coach.
These two overlap greatly, but at any given time...I am in charge and respect will be given. This is something that really bothers me with many young coaches. Don't be a friend to your gymnasts, be a professional. After all...friends are free, professional coaches are not.