  One of the things that bug me the most, is when a person is in the line to order and they're on their mobile phone. Not only is she trying to deal with the person on the other line, but she's also trying to figure out what she wants to eat.
That bugs me, get off the damn phone or else I'm going to slap it out of your hand with my cash register . It takes me five minutes just to get her attention, only for her to whisper right before she steps up to my register, "Sorry, hold on the girl is being impatient. " Uh...no. I'm trying to get my job done, and you're not helping at all you self rightious wench.
After she giggles, and says an overly dramatic "Oh yeah, I know.." I give her the brightest smile I can manage after seething. "Hello, may I take your order? " She blinks a few times, and then I realize, she's still listening to her friend on the other line. "Wait wait, hold on, I told you the girl is being a pain. " Holy crap lady, if anything, you're the one who is officially the pain in my toosh .
I smile, again, and repeat the question, only for her to go on about fifteen minutes asking me which is better..the chicken? Or the chicken. I understand so much more why people spit in their customer's food. But yes, anyways, enough about that lady. I'm sure I'll have many jerks today at work, but I'll cope. If not, I'll just turn to my old friend Sui Cide . :D 
