You shouldn't be concerned that Dinky behaved in a territorial way. Completely natural. Max was fascinated with new little brother when he brought Teddy home, but Max still guarded things like the piddle pads, beds, and his humans. Strangely, he didn't mind Teddy in his food bowl. Max went ballistic when I tried to offer Teddy his crate that Max never used for much of anything. Silly boy.
All of the territorialism and jealousies were worked out over time.
