1. That one customer who thinks they're hilarious:
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instagram.com / Via Nickelodeon
So original!
2. The customer who comes in five minutes before closing:

Nickelodeon / Via Twitter: @okmute
"Ya'll are still open, right?"
3. Those customers that freak out on you, then come back a week later:
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instagram.com
Well, well, well — look who it is.
4. The customers who think they're being generous, but are actually just completely unaware:
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instagram.com / Via Sony Pictures Television
Wow, how very thoughtful of you!
5. The tables that ask you to sing them happy birthday:
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instagram.com
Why would anyone want this? Do you enjoy being sung at? I don't...
6. The table that prays before they eat:
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instagram.com
Alrighhhhhht then.
7. Customers who don't even TRY to clean up after their children
View this photo on Instagram
instagram.com / Via Lionsgate Films
Does this look like a daycare?
8. Those customers who complain on Yelp instead of IRL:
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instagram.com
Why didn't you just say something then?
9. The diners who have literal novels worth of allergies:
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instagram.com
Allergic to black pepper? Really? Realllllllly?
10. Those customers that ask you for every possible thing they can get for free:
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instagram.com
Ughhhhhh.
11. Those customers that bark their drink orders at you before you even get the chance to greet them:
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instagram.com / Via VH1
WATER! DIET COKE!
12. Or the ones that just ignore you altogether:
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instagram.com / Via Fox
Cool, cool. Nice, real nice.
13. The customers that threaten you by saying they know the owner:
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instagram.com / Via Warner Bros.
Well I actually WORK with them! (:
14. Those diners who ask you for nutritional info:
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instagram.com
Umm, this is a restaurant, NOT a packaged food.
15. The full-grown adults that still order off the kid's menu:
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instagram.com / Via History Channel
Can you not?
16. The customers who ask you questions they can clearly answer themselves:
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instagram.com
I don't know, why don't you look outside?