What to do With a Too-Big Shirt?

First you should show your boss and ask if you may have another smaller shirt. If the boss says no wash the shirt and put the dirty on high and hot as possible. If this does not work you can tuck it in and pull the shirt towards your back and tuck the loose fabric over your rear. If non of this works you should find a friend who can take it up for you. Maybe you should ask around you friends while you are attempting to shrink it in other ways.