This is a story of when the Ugly becomes the Beautiful!
Good for you Denise!
Luna will on occasion do that lower the head over the bone thing, and after living 9 years with me, it's now a pretty rare event. She doesn't get away with even that.
I pick her adorable Rottie butt right up and put her into a sit, take her bone and give it a good inspection while musing to her aloud about "Luna, what in the world is so special about
this bone" and then I give it back to her. That diffuses on the spot any inclination on her part to resource guard and heads off any propensity for possessiveness to escalate.