I checked with your friend and she thought you were with me yesterday. Have you been going out while I've been working my night shifts? What were you doing yesterday? Don't tell me you're playing around with a boy? 

(suspicious/angered)

I work long hours. All I ask is for you to focus on your studies... Not to fool around! (angered)

I didn't get the chance take my break today... We were so short on staff... (dejcted)