Y'all seemed to like the genre of in-universe notices hastily thrown together in a word processor, so here's another one.
While the yinrih's nonsapient ancestors were social, they did not engage in social grooming. Yinrih pups give and receive gestures of physical affection such as kisses (from sires and dams) and tail thumps (from litter mates), but as they mature they begin rejecting these gestures. Deliberate physical contact between adults, including between sires and dams in a childermoot, is vanishingly rare. Of course medical exams are an exception, and there is a gesture similar to an embrace, where one person presses the top of his head against the chest or side of another, that indicates deep gratitude or relief, but we're talking "you literally saved my life" levels of gratitude.
-human race meets new alien race.
-Alien race is, like, super cute.
-Humans infantalize them.
-The aliens, devoid of pride and hubris, recognize this as an advantage.
-take advantage of the humans and make servants of them.
-humans dont care because they think the aliens are dumb.
-aliens dont care because everything is brought to them on a silver platter.
The aliens are revealed to be cats or dogs
In Futurama, that essentially happened to cats. They came to Earth because their planet was getting hard to live on, they landed in Ancient Egypt and were worshiped into house pets.
It's all fun and games until they poop on your bed or eat your other pet.