Coffin Buddies Forever: Implies that your friendship is one step above "Best Friends Forever." Meaning that you will either be buried in the same coffin or next to each other in coffins touching each other. By ring buried so closely together, it implies that you will be together for ever in the afterlife..... or if you don't believe in the afterlife, together forever in the ground, as your bodies decompose into the same organic matter.
OMG, I think our friendship just reached CBF status, because we are way more that just BFFs!!!!!