Epic!

That describes best friends so well.

I like the concept, cheerful in way. Not sure you mean by "never drops the knife".

Your use of "but" is a little shaky, I think. This is especially the case in the third stanza. "But" usually signifies a contrast, but you use it to point out the similarities of the two subjects.

Aside from that, I quite like it. Warm in its simplicity.