It's the type of guest who has been a pain all night, isn't listening to what you're saying, and just won't accept that this isn't how things are done.
It's a time when you are playing it by the book because you know it will be difficult and you don't want management to have any reason to question your actions.
It's the type of supervisor who will bend over backwards because they don't want someone raising their voice to them...
...and will then scarper so you're left dealing with the guest for the rest of the night, who will think you don't know how to do your job and will make the next few hours of your shift hell.
I used to have this happen all the time when I worked on the bar. The guest refuses to acknowledge what you're saying, won't accept they're wrong and you're just doing you're job. The supervisor then makes them think they're right (THIS IS DANGEROUS), and that you're an idiot who doesn't know the procedures and policies of the hotel as well as they do, leaving you to deal with the consequences.
On the plus side if the guest continues to be a pain, you can go and see the supervisor's supervisor and tell him exactly what you think of the supervisor and why.
Irritatingly, on nights I now have to deal with an absent supervisor, courtesy of hotel guest relations and a 24hr telephone hotline.
Now, the guest who is being a chore can ring a guest relations operator who will bend over backless regardless of the problem, and duly ring me to tell me to do whatever the guest wants. Complimentary goods run rampant.
Don't get me wrong, I don't usually play things completely by the book. It is a GUARANTEED way to irritate people who would overwise be quite easy to get along with. However, there are some people you just cannot do this with...
...and at times like this you just have to remotely disconnect the phone in their room.