We need to sneak our way through the underground city, rather than face countless guards and bring down the wrath of an army on us. Sounds reasonable. As we hear a patrol ahead of us in a corridor, we duck behind the nearest door, hoping that the room beyond will be less dangerous.
We find ourselves in a small anteroom before what looks to be another corridor. With there being five of us and only four squares available, one of us would have to stand in the corridor, which seems like the sort of thing that would get a person seen when we're trying not to be.
Luckily, we're not in combat, which means our movement isn't restricted, and Nerrick's being a halfling lets him move freely between the legs of creatures bigger than him, which is the rest of us. So the four of us stand in the four squares, and Nerrick constantly jigs around, avoiding the need to enter the corridor and become vulnerable to whatever threat obviously lurks at the other end.
For some reason, though, the GM simply won't accept this use of a character trait clearly described in the rules, and callously shoves Nerrick in to the corridor, where, apparently, 'there are three guards testing a magical repeating crossbow, which is pointing at the archery target next to you', (he has a name, and Pasha is a valid member of our party, so that's a little rude, to be honest), 'and as you step out you hear it fire two crossbow bolts. Initiatives, please'.