Cheesed off

(Finn comes into the office where Li is working and he looks very angry)
Li: Hi Finn. Oh, you don't look that happy today ... Here, have a bit of cheese.
Finn: No thanks, Li.
Li: It's tasty! Italian cheese—my favourite.
Finn: Thank you, Li. But, I'm sorry, I'm just in a terrible mood today. Do you know I have to spend the whole weekend writing a report?
Li: Oh really ... ?
Finn: Well, the boss said my first draft wasn't good enough and asked me to do the whole thing again by Monday!
Li: Not much fun. Sorry Finn. Are you sure you don't want some cheese?
Finn: No. No cheese for me, thanks. I'm ... I'm really cheesed off!
Li: Cheesed off? Is that a medical problem ... ? You can't eat cheese?
Finn: No. In English, 'to be cheesed off' means to be really annoyed. I'm so cheesed off! You can also say 'to cheese someone off'—so, writing reports really cheeses me off.
Li: So ... now I know why you're cheesed off.
Finn: Yes, 'cheesed off' is today's expression in Authentic Real English. Let's hear some examples of how it's used.

Li: No need to be cheesed off, Finn. I can help you with your report.
Finn: Oh really. You're such a sweetie, Li!
Li: But you have to do what I say ... 
Finn: Ok ... what do I have to do?
Li: First thing: have some of this cheese!
Finn: Oh, okay. Mmm ... mmmmm ... this is quite delicious! Can I have some more?
Li: You see. I knew you would feel better after eating something. You weren't just angry—you were hungry! Feeling a bit better now?
Finn: Oh yes. Oh, lovely. Thank you. Now, let's get this done. Bye.
Li: Bye.