prosey

Recently I approached a co-worker because the person constantly has temper tantrums. these outbursts cause concern (voiced) by my clients during appointments. I asked my co-worker to be mindful of the atmosphere and please tone it down when we have outsiders sitting in appointments. The person agreed but soon fell back to the old ways. Last week it was particularly difficult. the person was slamming things around and beating up on the photocopier! I know! Anyway I brought this behavior to my boss. Among her comments were: "well, life's not fair!" and (this is the one I really want you all to reply to) "I cannot guarantee that the person won't do that again."

How would you reply, my boss is open to communicating with me about this and I feel that I can freely (respectfully) share my thoughts.