what a way to boost morale in the workplace and kiss-ups

this supervisor of ours is requesting I submit documentation from a physician stating that I was too ill to go to work when I was out for 3 days. I spend my lunch working, I arrive at least 20 min. before required time and generally leave at least 30 minutes past quitting time. In addition, I spend any planning time we are given doing just that and about 1/2 every weekend preparing for the week. Thus exceeds triple the time that any other teacher there dedicates to her/his job. he says he wants to raise morale and the way he thinks it is done is by planning pot luck lunches. I'll be damned if I'll spend an evening cooking at home and spending my lunch time eating with the teachers who complain when not in his presence, but kiss up to him. Be real.