29-year-old scratches her friend's car while borrowing it, refuses to pay to get the scratches fixed by a mechanic: 'If you cared this much, you shouldn’t have let me borrow it.'

She let her boyfriend drive the car after her friend explicitly asked her not to let anyone else drive while she was borrowing it. 

It's always a gamble to let certain people borrow your stuff. I never think twice about letting my roommates or close friends borrow my clothes, but not everyone can be trusted with your prized possessions. If you give your partner your favorite jacket, you might never see it again if you break up. You might have to fight to get it back, and even then, they could refuse. It's hard to lose something to a borrower who never intended to return it, but at least a jacket can be replaced.

One of the bigger gambles is replacing something a little more expensive than a zip-up hoodie from Old Navy. One time, I borrowed my college roommate's car to drive six hours back and forth, and when I returned it, the battery had expired. She thought it went kaput because I had left a light on, but when she took it to the mechanic, we discovered I was innocent, and it had just stopped working because it was a four-year-old battery. I was so grateful that the battery hadn't halted on our way to or from our road trip, and I was extremely relieved that nothing worse happened to the car. I was stressed out the entire time that we were going to get into an accident, and I would have to come back to our apartment with my tail between my legs and perpetually apologize for the destruction of my close personal friend's motor vehicle. 

Some people don't have any shame about potentially harming their friends' cars. They are the reasons that rental cars are so expensive, and they shouldn't be trusted with anyone's personal car, even if they claim they "need it for an emergency." The hard part is figuring out if your friend is one of those people.