They’ve got probably more than 50 toys and trinkets they can play with, including lots of chewed down bones. So why does one ALWAYS want what the other one has at the exact time when the other one is playing/chewing it?
They’ve spent an evening of robbing each other. One distracts the other, moves in steals bone – the other repeats the theft.
One barks so they both go running off (at absolutely nothing, no reason for bark at all) and then whoever gets back first gets the bone.
And this is a bone, years old, that each could have had whenever they wanted – only became interested when the other wanted it.