Although every family is different in some way, many at least feel close enough that they'll help each other out in times of need.
Of course, there are degrees of how reasonable a request from a family member can be. But if they're in a tight spot and they're not asking us to move a mountain, we generally feel compelled to lend a hand.
Unfortunately, we can sometimes find that people in our lives will take a mile if we give them an inch. And it's hard to find a better case of that phenomenon then a situation that recently befell one Reddit user.