Well, for a newcomer here, it has been an interesting insight into the minds of some of my fellow dopers.
Entertaining as hell, as well.
I am SO happy I don’t have a roommate!
And all of my psychotic friends are either dead or institutionalized.
My answer to your question would be whenever you need to do so. Since you say she’s using “the biggest bathroom stall” I assume that there are other stalls available that can be used for their intended purpose, but you’re declining to do so because you don’t want to disturb her. For me, bathroom needs trump anyone else’s need for privacy to use a phone; if she complains about your use of the bathroom for its intended purpose I’d point out that there are meeting rooms she should be using.
That is my dream. I’m currently accepting offers of grants to help accomplish this dream.
Dear Doctoral Advisor:
How about you actually read my emails all the way through before you respond to only half of the content and compel me to write to you again? It would save us both a lot of time if you just answered all of my questions at once.
Oh, and while we’re at it, how about not trying to write the most cryptic fucking email imaginable? “Yes, sure, that sounds right.” What sounds right? “No, something is wrong.” What is wrong? I’m just going to keep asking, because I have no idea what the antecedents to those pronouns are.
You are a highly distinguished professor, by anyone’s measure. I’m a lowly PhD student scum-of-the-earth. I will never be a successful professor, I guess, because I can’t see myself turning into you.
There is a young feller at work who sometimes needs me to do small tasks for him, such as place an order. I don’t mind. My problem is that he will make the initial request, then check back with me an hour later, then email me a while after that, then ask me when he runs into me at the coffeepot, then check again before we leave for the day, etc.
I have always accomplished these things in a timely manner without the benefit of being constantly pestered. Even when I do a task right away and let him know it’s been done, he still shows up at my desk wanting to know when I think it will come, “you took care of that, right?”, etc.
I’m beginning to feel rather insulted about it. Apparently he doesn’t think I’m capable of getting things done on my own. We’re at the point now where every time he approaches me I fantasize about kicking his conscientious young balls right up to his chin. Settle down, Beavis!
Ha! In a small way, reminds me of when I send my boss and email that says, “Do you want x or y?”
And he responds, “Yes.”
Ha! 
LurkMeister,
You are correct! Baby steps though - I may try just flushing the toilet at her next time as a warning…
That happens with one co-worker so frequently that I now respond to all of his emails using a Magic 8-Ball. He hasn’t caught on yet.
Him: “Do you want me to take bug <x> or do you want to fix it?”
Me: “Outlook not so good.”
Him: “What? Are you going to fix it or should I?”
Me: “It is certain.”
Him: “What’s wrong with you? Are you going to fix bug <x> or not?”
Me: “Better not tell you now.”
Him: “ARE YOU FIXING BUG X”
Me: “You may rely on it.”
Him: “God DAMN you’re irritating.”
Like I told a friend once: the words “logical” and “wife” shouldn’t be used in the same sentence.
I have this co-worker, too. I had to stop giving him options. “Do you want X?” If he wants Y, he’s gonna have to reject X first.
Removed at OP’s request. -Miller
Look, officemate:
I know you seem to work best when your corner of the office is a completely disgusting pigsty, but maybe you should accept the fact that when you can’t find a single thing that you’re looking for, it’s time to clean up a bit. With that in mind, quit stealing my stuff! Just because you can’t find your own things doesn’t give you licence to take mine! And when I confront you about it, quit saying “it’s just a pen” or “it’s just a pair of scissors” or “it came from the supply closet anyways”. That is not the point! The point is that I never have the things I need because you always take them and then lose them. If it’s so easy to get stuff from the supply closet (it’s not - it’s locked and we have to sign for the stuff we take), then do it yourself, you arrogant little fucker.
And also, stop sniggering at the lame Youtube videos that we all know you watch all day instead of doing any actual work. We can all hear you, even though you have your headphones in and can’t hear us. It’s really annoying.
In short, please screw off and die. The rest of us are trying to be productive. Thank you.
Try this:
9:30 a.m.
Young Feller: Hey Dung Beetle, can you do [small task] for me?
Dung Beetle: Sure, come by my desk at 2:30 p.m. and I’ll have it ready for you.
Young Feller: Sure, that’ll be fine. Thanks a lot.
Dung Beetle: My pleasure.
11:00 a.m.
Young Feller: Hey Dung Beetle, did you finish up with [small task] yet?
Dung Beetle: Is it 2:30 p.m. yet?
Young Feller: No, it’s 11:00 a.m.
Dung Beetle: Then come by my desk at 3:00 p.m., and I’ll have it ready for you.
Young Feller: But, before, you said 2:30 p.m.
Dung Beetle: Yes, and you agreed to that. Since you’re changing when you’re asking for it, I’m changing when it’ll be ready. Do you want to see if you can get me to change it to 3:30 p.m.? All you have to do is . . . ask me.
Lets see, I have so many… Here is one. People who tell stories online that when I read them, it sounds like there story is being addressed to me, then in turn never having the balls to tell the actual person who is the main annoyance.
I think someone has a case of the Friday evenings. 
Oh come on now. Humans are hardwired to have a negative emotional response to things that is exaggerated far beyond what rationality would apportion. It’s better to let off the extra steam in a random internet forum so that one can have a reasonable approach dealing with the real life people later without inappropriate fury, and without the consequences that come with shoveling negativity at people one has to see every day.
Or would you rather we all come to work or Thanksgiving dinner with machine guns and blow every one away because of some minor thing that happened to really get on our nerves?
Hey jackdavinci, can I be put on your list of people who get on your nerves? Can I, can I, can I? Please, please, please, please? Come on! You know you want to.
I’m not touching you, I’m no touching you. Pttttthhhhhhhhhh! Are we there yet? No, you are!
Classmate: Yes, I’m being passive aggressive by ignoring your emails. If you ask me for my homework again, I’ll be aggressive aggressive and kill you.
Heh - I did that to a very nice lady for a volunteer support group I work with. We have a meeting every two weeks; if it gets cancelled, I reliably send out an email as soon in advance as possible. Do not email me every two weeks and ask me if we have a meeting - yes, we have a goddamned meeting! Get a calendar! Put marks on it with a pen!
I am ready to kill my stupid cat. Horrible beast.