I have a co-worker using my coffee mug at work. I want to make him stop without sounding like I'm being picky. I have tried making the point indirectly that the cup belongs to me but he still uses it.

Our cleaner cleans the cups and puts them on a tray in the kitchen area, he usually arrives in before me too so I can't just nab it before he gets here.

What would be the best way to go about this, as I said, without sounding like I'm being fussy.

Edit :-

I got to work 30 minutes early and..

I got my cup back!!

Today was a good daycup

  • 3
    I've been in places where people have "claimed" cups as their cups in a communal area. They do not own it, they simply like the cup and become possessive of it. I'd venture to guess your coworker assumes this to be the case also.
    – pi31415
    Nov 18, 2014 at 11:26
  • 10
    "I have tried making the point indirectly" <--- I found your problem.
    – Casey
    Nov 19, 2014 at 17:29
  • 3
    You should state what country/culture you are in.
    – user29768
    Nov 19, 2014 at 22:42
  • 4
    1. Is the cup property of company or your personal purchase? 2. If it is owned by company, are you sure that your colleague does not think abosolutly like you - i.e. you are using his cup?
    – i486
    Nov 20, 2014 at 8:27
  • 4
    This question is a little akin to asking how not to sound picky while being picky. I would imagine that many people simply don't care who is using which cup, and your colleague might fall into this category. Your colleague should be mature enough to understand that his attitude is not the only one (and that you absolutely have a right to use your own cup exclusively). Trying to window-dress your pickyness might just make you appear picky and passive-aggressive. If you're picky, be picky, it's not the worst quality; embrace it and people will respond positively to it, I know I would!
    – quant
    Nov 21, 2014 at 1:00

8 Answers 8


In most offices, it's generally understood that items like this which are left in public areas are available for public use. The simplest solution: don't leave it in a public area.

Clean the mug yourself at the end of each day, then store it securely in your workspace.

  • 26
    I've never worked anywhere where this is true. It's generally considered that generic looking cups, etc. are for general use but it's usually understood that any distinct looking mug is probably personally owned and shouldn't be used. Nov 18, 2014 at 15:55
  • 8
    @JackAidley it's the complete opposite in my office. If a mug, plate or utensil (or even food outside the fridge!) is in the kitchen (common area), it's considered fair game for anyone. If you want to keep something for yourself, you have to keep it secured at your desk.
    – alroc
    Nov 18, 2014 at 16:20
  • 1
    It sounds as though this OP's office has a custom that "things left in public places are for public use." Different offices, different customs. Getting along with others in the workplace often means following whatever the established customs happen to be. Nov 22, 2014 at 15:05
  • 5
    I once had a similar thing happen to me. I took a mug in to work, left it there, and before I knew it the director of personnel was using it! I got righteously indignant and considered going over his head to the owner of the company - and then I remembered something. I'd taken that mug to work because I didn't like it much! So far as I know it was still around somewhere when I left that company... :-) Morals of the story: 1) if you like something, don't take it to work. And 2) if you take something to work, don't get pissed if someone else grabs it. Nov 23, 2014 at 1:51
  • Something like a "Hey Bob, I brought that mug in to work, can I have it back when you're done using it today?" is too much?
    – Nick T
    Nov 10, 2016 at 19:23

enter image description here

  • You may wish to buy a lock mug (it has a large hole in it to deter would-be cup thieves - Buy online here

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  • Or you could just keep your cup in your desk.
  • 94
    +1 just because it's hilarious that someone invented the lock mug rather than just storing their mug in their desk. :) Nov 17, 2014 at 22:55
  • 9
    @CullenJ - It's both passive-aggressive and just plain aggressive in one fell swoop
    – Richard
    Nov 17, 2014 at 22:57
  • 4
    And in the modern workplace, not all of us have desks anymore. We've just got tabletops.
    – shoover
    Nov 17, 2014 at 23:42

Put your face on the mug, this will make sure everyone knows it is yours.

enter image description here

  • 29
    It didn't work out that well for him
    – dyesdyes
    Nov 18, 2014 at 9:54
  • It's clear it's his. It's just that he doesn't care.
    – o0'.
    Nov 18, 2014 at 10:22
  • 8
    Perhaps putting your face on the inside of the mug will have the desired effect.
    – talrnu
    Nov 20, 2014 at 15:40
  • 6
    @kmonsoor The IT Crowd, Season 1, Episode 4 Nov 23, 2014 at 21:54
  • 2
    Won't work because people are not looking at the bottom of the cup
    – user1023
    Feb 11, 2015 at 15:26

What would be the best way to go about this, as I said, without sounding like I'm being fussy.

  • Clean the cup yourself.
  • Keep your cup at your desk when you aren't using it.
  • If someone still tries to use your cup, say "Sorry, but that's my cup."
  • If someone continues to ignore your request, and takes your cup even after explicitly being told that it's yours, then go right up to them, take the cup away, empty the contents in the nearest sink, and return it to your desk.
  • 8
    I like this solution. The cup belongs to you, you've clearly stated the cup belongs to you, and if they persist, you are just asserting your right to your property.
    – Doktor J
    Nov 18, 2014 at 23:20
  • I was looking for a non passive-aggressive answer to upvote, and this one succeeds on the 3rd point, but is actually aggressive on the 4th...
    – Phil H
    Nov 20, 2014 at 14:01
  • 4
    @PhilH considering that somebody is going into your workspace to take something that you have explicitly told them is yours I think its a reasonable response. It's possible to do it in a nice manner - You definitely don't want to be angry about it or it may become a joke to steal your mug and get you riled up. Nov 20, 2014 at 16:00
  • @DoubleDouble: No-one has explicitly told the coworker - OP says they indirectly mentioned it, so who knows if the coworker even heard him? Also the context of communal mugs is everything here. Taking the cup and pouring it away is definitely angry, and aggressive, and childish.
    – Phil H
    Nov 21, 2014 at 9:57
  • 2
    @PhilH "Politely, without being sarcastic or testy, tell your coworker that it is your mug, and you'd like to use it" sounds like the same advice to me - you are taking back your cup.. and I assume you wouldn't drink whatever the other person was drinking. Nov 21, 2014 at 18:20

Your coworker obviously likes the design on your cup.

Why not treat him to one of his own? This is a friendly way of saying "Don't use my cup", without having to actually say it.

Hey, I see you liked my cup so I bought you one as well!

If you want to be able to tell them apart, you might be able to get one that's slightly different but similar enough that he'll still enjoy it.

  • 16
    This is not only the most gracious proposal here but also the most effective. It's stronger than a hint but isn't aggressive in a way that gives people anywhere to fight back from. If they have any sense of saving face all they can do is accept the gift and hence-forth leave your mug alone. I've done much the same thing with writing implements. Gift that co-worker the pen/pencil they seem to fancy so much and yours will suddenly (and in my experience permanently) stop disappearing from your desk. With any luck the atmosphere will even be lightened and their manners will improve.
    – Caleb
    Nov 19, 2014 at 21:18
  • 14
    @Andy "A generous person will prosper; whoever refreshes others will be refreshed." Proverbs 11:25 There is much to be said for undeserved kindness; you'd be surprised at how people respond to it. No, it's not 100% effective, but what is in the realm of social problems? Contrary to what we might want to think, people aren't quite as simple as Pavlov's dogs.
    – jpmc26
    Nov 20, 2014 at 1:59
  • people aren't quite as simple as Pavlov's dogs, edit, most aren't... some though... still I like this answer. resolving in issue in a manner that is win-win for preventing further issues as well as improving your public image at the company... that's worth a few bucks. Feb 11, 2015 at 17:02
  • 1
    This would be a good solution for one offender. However, I have random people taking my mugs (dozens, potentially hundreds) and I do not intend to buy a mug for each and any of them. Feb 27, 2015 at 15:36
  • @SeanPatrickFloyd If you mean your mugs are being stolen, that would be a different problem, imo. However, if yours mugs are coming back to you after someone else uses it, perhaps just a tray of communal mugs might do the trick. It doesn't have to be one per person; just a few that anyone can use.
    – jpmc26
    Oct 1, 2015 at 5:39

What I did to make sure no co-worker uses my mug, is to use one with following text on it:

I love (your name here)

Preferably with additional big hearts, your picture or whatever floats your boat.

Seems to work better than just "This cup belongs to...", but it might really depend on your work environment/personality. Certain people will not mind taking another persons mug (even if their name is on it), but taking one with "I love ..." is just hilarious in most cases.

  • 5
    I work with a guy who has a very pink Disney mug for exactly this reason. It works very well.
    – Gusdor
    Nov 18, 2014 at 10:10
  • 1
    This is both practical and fantastic. Your mug might still be stolen... but at least you can get some good laughs out of it. Feb 11, 2015 at 17:05

I don't know how much feedback you've given this person, so I think you need to be direct. When you see him with your cup, take another community cup, walk over to the person and ask for your cup back. He can pour what is left into the empty cup.

This person is being intentionally rude, so you need to provide some negative consequences for stealing your property (And borrowing without permission is stealing.).

  • "Borrowing without permission is stealing". Nope, you need to hit a dictionary. "Steal: take (another person's property) without permission or legal right and without intending to return it."
    – occulus
    Nov 18, 2014 at 14:28
  • 6
    @occulus: ah, the case law. In England, cinema employees without permission taking tapes home to watch and return was held to be theft because watching the tapes causes significant material wear and tear and thus the owner was permanently deprived of a right of ownership (namely: to consume a limited resource). Doesn't apply to mugs unless you damage it, but the general point is that intending to return the property is not inherently sufficient regardless of what the dictionary says :-) Nov 18, 2014 at 14:57
  • Let me rephrase then: it is incorrect to make the blanket statement "And borrowing without permission is stealing".
    – occulus
    Nov 18, 2014 at 16:34
  • 2
    Actually that does apply to mugs because the seasoning of a mug is super important. Coffee doesn't taste right from a brand-new mug, and if you put something wrong in it, like OJ, that flavor remains for a while. So yes, it is causing wear and tear on the mug.
    – Jasmine
    Nov 19, 2014 at 18:38
  • 2
    @PhilH - That's why I questioned how much feedback the OP gave and suggested being more direct. If the person continues to use someone's cup knowing full well they don't want them to, what do you call that?
    – user8365
    Nov 21, 2014 at 18:28

Talk to your coworker

Politely, without being sarcastic or testy, tell your coworker that it is your mug, and you'd like to use it - point out that it is moved by the cleaner, perhaps, and that you intend to store it on your desk to avoid causing problems.

If that seems fussy, well so be it - be fussy, or don't be fussy, but don't be fussy and try to hide it, or make it some unsaid grievance. The essence of this seems to be that you don't like what they're doing but you can't quite bring yourself to acknowledge the pettiness of the behaviour. If you think it is that petty, why do you care so much?

The problem with silently asserting ownership

I'm slightly troubled by many of the existing answers; they are either evasive (silently hoard the cup), passive aggressive (lock mug, writing your name on the mug, add bitterant(!!)) or outright aggressive (take mug from colleague, pour contents down sink). Aggression (passive or active) and evasion are not constructive ways to behave in a community like the workplace. If you are passive aggressive, and it happens again, next time you'll be angry, and quite possibly with no one knowing why.

Expectations in society

This is all about expectations. I'm not saying mugs should be communal, I'm pointing out that it is very evident that mugs are assumed to be communal at this workplace. The OP acknowledges that, and that it will seem petty to point out that he/she owns the mug. In that context, it is not about the facts of possession, but about how you establish that you are going to break with the general rule.

Of course if you own something you own it, but the context is that the coworker sees 1 mug in a collection of many that he/she safely presumes to be communal. You have to look at it from the coworker's perspective, and presume innocence.

Society in general functions on the basis of expectations, and different cultures have different expectations. For example, in the UK driving is very rule-bound, and you expect others to obey the rules. My colleague tells me that in his country, people ignore most of the rules, so you don't expect others to obey the rules. Neither is universally the 'right' system, but it is important that you know which you are in and make it clear to others if you are about to go against expectations. It is more dangerous to break the rules of the road when everyone expects you to obey them, because they won't be looking for people who do that.

Here, the expectation is that cups in the kitchen are communal, that you are free to choose a cup and use it. In that context, someone having their own mug is not wrong but it is different, so all they need to do is communicate that with the fellow members of the community.

Don't go through life thinking that your rules are the only right ones, and that everyone else should stick to your system, or you will rub completely normal people up the wrong way and make difficulties for yourself.

Is it that hard to talk to someone about a mug?

  • 3
    In what way is storing the item one purchased for one's personal use in one's own desk "silently hoarding the cup"? Is keeping my reading glasses in my desk "hoarding the glasses"?
    – alroc
    Nov 20, 2014 at 14:12
  • 1
    @alroc: Because you are going out of your way to keep the cup somewhere instead of just saying something. Glasses are clearly a personal item, but as is clear in the question mugs are not considered personal items in this workplace. So it's more like making a stapler yours by hoarding it than like keeping your glasses in your drawer. If it is left somewhere, washed up, and put back in the kitchen, nothing has been said and the cycle can begin again.
    – Phil H
    Nov 20, 2014 at 14:17
  • 3
    I have to disagree. If I purchase an item such as this with money out of my own pocket I should be free to do with it as I wish, including keeping it at my desk for my exclusive usage, without judgement. It's not "going out of my way" because my desk is already the one place in the office designated as "mine" where it's understood that people respect personal items and space.
    – alroc
    Nov 20, 2014 at 14:23
  • @alroc: Adding to my answer, as commenting is getting long.
    – Phil H
    Nov 21, 2014 at 9:39
  • 2
    @JamesRyan please read my answer above. You clean the mug and put it away in your desk. If the cleaning crew is rifling through cabinets and drawers, you have a major problem in your office.
    – alroc
    Nov 21, 2014 at 13:53

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