It's no secret that Stumpy is possessive. About everything.
Whatever the Berner gets
Stumpy gets, too. She gets all treat, pats, scritches first and last.
Still, she insists on guarding her treasures.
To the point where she sometimes won't take her eyes off of Mr. B, to enjoy her treat. She's too busy giving him the evil eye, even though he could care less, to take pleasure in her treasure.