A cafe has restrooms that lock; you have to get a key at the counter. But often, people don't close the bathroom door behind them as they leave and return the key to the counter.
A customer, finding the bathroom door ajar, doesn't need the key, so she goes in, closes the door, and starts peeing.
Another customer enters the cafe, picks the up the key, and heads straight back to the bathroom, opening the door and unintentionally ambushing Customer #1 while she is peeing. Then she enters the bathroom and they make out. (Ok, so maybe the last part wasn't needed.)
Were you thinking laterally enough to foresee this?Everyone knows of course that locks and keys are both part of a system that lets you into places and keeps people out.
Why do we carry keys? To keep people out of places... regardless of where you might be at the moment, or whether those places are locked ;-)
If that was too easy: why do we carry keys? To signal that a space is locked. An untrustworthy stranger, seeing your keys, assumes you lock your house, even if you don't. Customer #1, wanting some girl on girl action, can dupe Customer #2 into ambushing her by leaving the key out - signaling the bathroom is empty.
