I was dating this girl a couple of years ago and we were pretty early on, but she wanted to spend the night. And we were cool so it wasn't an awkward thing, but what I figured out as that she didn't necessarily want to stay the night as much as she was afraid to go home at night. Her reasoning, "My mom just broke up with a police officer and they harass us now." Shes from a super small town with a police force with a reputation for having nothing to do, but staying busy. But even when she said it I thought she might be being dramatic. Now I get it. This type of behavior is ridiculously childish and it might not be the norm, but it seems like something someone could stop.