Unfortunately for Denver, he got into the kitty treats again. But, you know, you gotta give it to him – Denver is very, very sorry for what he’s done. Denver is on the verge of tears. Poor Denver.
Oh, and, about what Denver’s actually doing. Redditor beffjaxter explains:
To explain a bit more on why the dog is bearing its teeth, for those that do not know. This is known as “grimacing” and in the breeds that demonstrate it, it is a sign of submission. My father in law has a German Malinois that exhibits this behavior when in trouble or even when happy to see you.
UPDATE: Last night, embedding this video was disabled by request. Watch it on YouTube.