I want to RIP my hair OUT!

This penticton chik is driving me bonkers. Last nite I was working with 3 of my friends and Erin (penticton chik) was in room 23 which is right by the tills. One of my friends was on the till beside me so we were laughing our whole shift and I finishd up serving a customer and as they were leaving I started to clean my till but I was laughing and Erin comes out of room 23 and flipped at me for not working! Then she told me to go bring in the bullars so I said okay and it was where I found my happiness. I went and did them and she stood there talking to another guy so when I walked by I was like Erin arent you suppose to be working? Her face went flat and she was soo mad! It was hilarious. I just walked by and laughed. Today after work she said a really rude comment and I am not going to repeat it because its inappropriate and so I faked slapped her. I did not literally slap her and shes like ugh are you joking me? I was like its a sarcastic slap, its not like I actually slapped you. And shes like I dont care I am your boss. I was like w.e Im off shift. Then she went and told the Asst. Manager. She is such a bi***. Technically she isnt my boss, she is my supervisors assistant. My supervisor and Store manager dont even like her, either do any of the cashiers. They act nice but everyone talks about how much they dislike her behind her back. I cant stand working with her and I am so glad I have 3 shifts left!