Getting drunk at work the day after thanksgiving.

The is my first time having to work on the Friday after thanksgiving my boss is an ass and won’t let me take it off even though she’s off so my plan is to spend most of the day drinking not a lot but maybe a few drinks to make the day more mine and fun but I am worried someone I work with will say something. I have my own office but I share it with one other person who may be there. I was thinking of going to the bathroom to have a drink but any tips on how to hide it or maybe an excuse I can say. I was thinking of saying I had just taken cough medicine or something or wearing a mask and saying I might have Covid.