Cabin crew may always have a smile on their face, but that doesn’t mean they haven’t experienced their fair share of frustrations.

Smiling is a part of the job, and so is dealing with hundreds of passengers each day, so you can imagine that they’ve dealt with some headache-inducing situations.

Speaking to  Business Insider, flight attendants revealed the irritating things passengers do that make their job a lot harder.

1. Unpacking overhead bags during a flight

Whether you really need your earphones, or you left the book you were meaning to read in your bag, opening the overhead to get to your bag is not only frustrating for airline staff, but the passengers around you.

“The best way to maximise everyone’s time and make your fellow passengers not hate you is to keep all of your necessities in the personal space at your seat,” domestic airline flight attendant, Haley Fox told INSIDER.

“If you come onto a plane, then get to your seat and have to unpack your big roller bag in the middle of the aisle just to get to your headphones, you are the worst.”

2. Ordering more than one drink at the same time

“When someone asks for a water, a coffee and a Diet Coke, it slows down our service,” said Jennifer L., a fight attendant for a US airline.

“We have to get through the whole cabin. So instead, ask for one drink and we can always come back to give you something else after we’ve gotten through everyone.”

3. Ignoring them when they say hello

This one is pretty self-explanatory. Rude behaviour should never be tolerated, but with hundreds of passengers being greeted each day, at least one is bound to completely ignore you when you say hello.

“If I greet you, please have the courtesy to answer me back,” said Jennifer.

“Don’t ignore me or pretend I don’t exist. I’ve woken up probably earlier than you and will be working past the time you arrive at home. So be kind and remember to have manners.”

4. Asking for an upgrade to first-class

“Flight attendants do not have the authority to upgrade you to first class,” said Jennifer. “Those seats are not up for grabs unless the gate agent upgrades you or you pay for a first-class seat prior to entering the aircraft.”

5. Crowding their space

While it’s perfectly fine to go for a stroll on a long-haul flight – no can be expected to be sitting down for hours on end – be mindful of where you decide to stand.

Blocking galleys and jump seats is never a good idea.

“If you want to get up and move around during the flight, don’t utilise our only workspace as your stretch zone,” Fox said. “I don’t come to your office and put my butt in your face, please don’t downward dog and lunge around in mine.”

6. Demanding a special meal during a flight without giving notice

Believe it or not, planes aren’t stocked with an endless supply of food. Instead, they usually only carry the required amount needed for each passenger.

Which means if you need a special meal, you need to put in a request before you hop on board.

“We do not have everything,” Jennifer said.

“Please don’t ask us if we have soy milk or some kind of food we didn’t say we had. If you have certain diet restrictions or don’t like the options we have, please bring your own food.”

7. Not flushing the toilet

This one is quite obvious. Toilets in planes aren’t the most pleasant experience, but despite the long lines, the terrible lighting and the confined space, there is zero excuse for not flushing the toilet when you’re finished.

8. Walking around barefoot

A flight attendant took to a Reddit thread in 2018 to share just how filthy the habit of walking around barefoot on a plane really is.

User Seeyou_Never wrote: “DO NOT WALK AROUND BAREFOOT. Pee and poop happens, all over. I feel like I witness an ‘accident’ regularly; in their seat or in the lav. People get nose bleeds, or their wounds open.

"Obviously when we land, it is thoroughly cleaned. But in-flight our resources are limited.”

What is something that annoys you during a flight? Let us know in the comments below.