People love to test boundaries, especially when it's not their own boundaries.
And people also love to protect themselves first and foremost, no matter the cost to others.
From that equation, we can surmise that some people will cross boundaries while protecting themselves in such a way that it will significantly impact someone else. And that action makes that person look like a total jerk.
Here were some of those answers.
Small Feelings, Small Minds
When I was in grade school, my family was one of the poorer families in a private Catholic school. I didn't know it at the time, but I was only there because of loans from my wealthier uncles. So it was a rarity that I ever had money , whereas most of my classmates had at least some kind of allowance.
I don't remember how, but one day I had a few dollars. One of the most popular guys in my grade did not have money for lunch, and I packed every day anyways, so I lent him the money needed, thinking we might even become friends as a result.
Several days later he still hadn't paid me back. So I asked him nicely about it. His response was to loudly sigh and say, "I don't feel like dealing with this," reach into his pocket, and pull out the amount he owed me in quarters and dimes. Then instead of handing the coins to me, he threw them across the room onto the floor, making me go search for them on my hands and knees beneath chairs.
It has been over 20 years since that happened, and I feel petty and small whenever I think about it. But I still can't help but think about it occasionally. And whenever I do, I still get the urge call that guy up and say, "screw you".
Lies On Principle
I used to work at KFC, on my first day they had me on register, and this lady walks up to order. I was moving rather slowly so I told her it was my first day and apologized for taking so long. She seemed super nice and understanding, so I thought I was in the clear. As I handed her receipt she says "Where's my free drink? You told me I got a free drink." I definitely never said this and was confused as to what to do, because it was obvious she was trying to take advantage of it being my first day. She then waves my manager over, tells her I promised her a free drink and that she expects a free drink now. My manager threw me a dirty look as she hands this lady a cup.
Luckily a co-worker was standing nearby and confirmed that I never told her anything about a free drink, so my manager let it go.
I used to be an architect, and was on a team that won an award for a building. The team was supposed to fly to another city, go to the reception, stay overnight and fly back the next morning (and come to work in the afternoon) all on the company dime. First time I had been able to do something like that.
The project I had moved on to when this was going on was a dumpster fire because the manager didn't have the spine to stand up to the constant changes of the client.
He told the whole team that we needed to work all weekend on the latest changes to still meet our original deadline on Monday (changes to 12 multi-story buildings) and said I couldn't afford to miss any time. So I had to tell the other team I couldn't go on the awards trip.
After the team left for the airport, I found out from a 3rd party that the client had given us an extra 4 days on the deadline because of the last-minute changes, and the manager kept that from the team on purpose so we'd work for free on the weekend.
My girlfriend asked me to buy some wine bottles as a gift for her and leave them at her place while she was at work. I did as she asked. A few hours later she texts me saying thanks, but she had been doing some thinking, and felt it was time we saw other people.
At least she said thanks...
My dad had a baby with his then 18-year old girlfriend when I was 15. He gave me a debit card to his bank account and she had one too. He was a truck driver at that time, so he instructed me to withdraw $40 from his account every Tuesday when he got paid.
My mom was broke, he wasn't paying child support, so this money was my lunch money and money for necessary items like tampons. Dad's girlfriend got the whole rest of his check for her and the baby.
For a while, the girlfriend was buying the baby some new swing or bouncer that he didn't need every week. One week, she wanted to buy this huge saucer thing with all of these toys attached to it. It was really expensive and she fell about $40 short of being able to afford it. So, she got up really early in the morning (like 5 AM) before she knew I'd be awake to go to the ATM and she withdrew all of the money so she could buy the baby the swing and I wouldn't get any money to eat with.
I had been seeing this boy for quite a few months, casual and friendly, things were slowly progressing and it was going good, or so I thought. Anyway I was having some people over for my birthday and the day beforehand he kept going on about how he was excited to come. Day of, I hear nothing from him. A few hours after everyone else had arrived, I check snapchat and see he's drinking at another party. Drunk me sends a message a few hours later saying that what he did wasn't cool and a simple message saying he wasn't coming would have been fine. He doesn't open it for over two weeks. When he finally does open it, he doesn't reply and blocks me on all forms of social media. OK
My Dad's funeral was on valentines day, and the guy I was dating at the time said he didn't want to send me flowers that day (Obviously I was getting flower delivery's for the funeral) and said he promised to make my birthday 3 months down the road extra special... On my birthday, he asked me to pick him up at the airport 2 hours away, and dumped me as soon as I pulled in his driveway.
Roommate photoshopped bills to be more expensive and put them back in the mail so she could collect more money from us to keep for herself. Went on for months before we figured it out. All while lecturing us about how we were very wasteful people for leaving lights on and turning the heating up too much. She'd rant about how we were all so much more 'privileged' than her any time a hallway light was on or the thermostat went over 67 in the winter. All while skimming A LOT off the top of those bills. What a terrible human.
Clean Up Clean Up
I let a friend use my house for a birthday party. understanding was that I was just providing the space, she'd provide the booze, liquor, food, and do all the clean-up afterward.
She got trashed, passed out, and at some point took an Uber home, leaving me with all the mess. her guests made a mess of the house and backyard, smoked cigars in the basement without asking if it was OK, and raided our liquor cabinet (including drinking a few bottles I'd been saving for a special occasion).
Jerks Without A Cause
My (now ex) in-laws promised to pay for and pick up our modest wedding rehearsal dinner catering and then an hour before they were supposed to do it, pretended they both forgot their wallets and loaned their car to someone.
The rehearsal was in a place 4 hours from their home and they were staying in a hotel for 3 days so obviously they had to have brought some form of payment. Also they went out to eat and went shopping in their downtime so again, this is clearly a really stupid lie. They didn't really have friends in the area so I'm not sure who they pretended to loan their car to or why and it was so ridiculous I didn't even waste my time pretending to ask. This was super-typical behavior of them though so we'd actually arranged our Plan B for this before we asked the in-laws if they could do it. It's just... such a dumb lie. These people were in their 50s.