Dear …
I would like to bring to your attention a situation that recently occurred. I have been notified that on __(date)__, __(name)__ had questions about my __(leave/leave of absence/vacation)__ and when __(he/she)__ was not able to contact you about it, __(he/she)__ chose to discuss it instead, with __(one of my coworkers/another employee)__. Not only was my privacy breached with this action, but __(name)__ had also relayed some inappropriate personal comments to this other employee regarding my __(leave/leave of absence/vacation)__.
I was very alarmed to hear about this incident and it has deeply concerned me. I feel that __(name’s)__ behavior was both unprofessional and inappropriate, particularly given __(his/her)__ position of confidentiality. If __(he/she)__ was not able to reach you for comment about this matter, then __(he/she)__ should have come to me with it, not to a co-worker of mine. In addition to that, __(his/her)__ personal opinion about it need not have been discussed with my co-worker. I am requesting that you please speak to __(him/her)__ about this situation in order that a reoccurrence may be prevented.
I have always been considerate about taking my __(leaves /vacation time)__, never misusing or abusing __(them/it)__. I always try to schedule far in advance, to make it easier for everyone. I know that you will be able to handle this situation quickly and capably, __(name)__, and for that I thank you. Your help with this is greatly appreciated.
Sincerely,