Fun idea entirely unprompted. (BBU, Pet whump/ Box Boy Universe Topic) but I will subject you all to it anyway.
If Riley and David, both trained as Guard Dogs, ever *met* each other at the same social event:
In my version of the BBU, Guard Dogs are encouraged not to trust each other, but upon the rare occasion that they ever meet in society, they often have a weird sort of grudging mutual respect, because they know what all of them are capable of. It takes one to know one, and they know each other.
So if their owners were to be at, say the same fancy gala...
David would find Riley registering immediately as Clear Threat. He assesses everyone he sees at some level of Threat between “Ignore” and “Attack If They Even Get Close”. All his instincts would read Riley as a very obvious and professional threat. He would be keeping himself physically standing a lot closer to his Principal, and ready to move at any second.
Riley would know David was a fellow trained professional but would also conclude within the first five seconds that David will hold back in little ways where Riley usually won’t. He’d know, and be probably correct, that if it came to a fight he could take David down. He’d also know that David came to the same conclusion just as quickly- and he’d probably give David one of his smiles. The smug, slightly malicious ones without teeth, that say “Oh yeah- we both know. Don’t even try it.”
They’d end up moving around the room all night following their respective Principals but eyeing each other like two territorial predators waiting to see if the other one dares to make a move.