FoolsSetTheRules
It's hard for Dean to choose; save Cas or grab his gun and shoot the thing. No matter how many times Dean has seen it before, watching Cas get hurt is something he tries to avoid. It didn't matter, that Cas couldn't feel it, or that his angel mojo would fix him up nice and pretty.
Didn't matter, because /Cas/ mattered.
The damn demon though, wouldn't be held off for long, and Cas could sustain a small wound if need be. Damnit, Dean hated to choose, but he needed the rock salt, and he trusted Cas enough to be able to protect himself.