Psst. Hey, bud. Come ‘ere.
You keep saying coup de gras. It’s coup de grâce. The s sound is pronounced: it’s not silent. When you don’t pronounce the s sound, you end up saying coup de gras. It’s coup de grâce. Coup de grâce means a finishing blow, literally a “blow of mercy” (i.e., to put someone out of his misery). Coup de gras would mean a “blow of fat.”
I don’t think that’s what you’re trying to say, is it?