That's not being a man, you're being a child about this and stamping your feet because you're not getting your own way.

[He frowns, voice level.]

Every man has a line he won't cross. If that's cold-blooded murder, then that's okay, that's his choice. It takes more of a man to stand up for what he believes in, than to crumble under pressure. You don't respect him, fine, tell him straight that friendship is out of the question now.