You shouldn't behave like this until you start coaching MS at least.
Seriously, somebody needs to take this guy aside and have a talk with him. Sometimes behavior can be modified by taking the right approach. My assistant used to be very hard on a select few of my girls, and still can have his days, but he really does care and just gets frustrated at times and lets it show. Whenever we discuss it, he is aware and makes a supreme effort to control it.
We are all human in this profession, and sometimes the best thing is to approach somebody in a responsible way and let them know the issues that you have with their behavior. If it is an emotional issue for you, it is probably better to have someone who is more emotionally detached from the problem deal with the issue. Having one level-headed person direct the conversation can really lead to some positive results and maybe have benefits for everyone involved.
Don't write someone off until you have attempted to deal with the problem and your efforts are rejected. And don't expect a 100% reversal in behavior, but steps in behavior modification. A lot of times, the person involved has no idea the impact their behavior is causing, or what they look like from an outsider's point of view. But with steady feedback and a commitment to succeed, a person can change for the better.