I'd read a short story online a few years ago where an astronaut is woken from cryogenic sleep when her ship encounters an alien vessel. It is implied that the aliens look like sharks, and they eat smaller sentient beings with whom they co-evolved and with whom they can communicate. The smaller aliens are raised as servants and are aware they'll eventually be killed and eaten. They express fear before they're killed, but the larger species doesn't consider them sentient. The predator aliens want to find the astronaut's home planet so they can eat humans. The astronaut befriends one of the servants and the predator aliens threaten to kill him if she doesn't lead them back to Earth. She pretends that she's willing to go along with them to save her friend but, shockingly, isn't willing to sacrifice the entire human race to save a single alien or to satisfy a trope.
The point of the story is that sentient species are unlikely to acknowledge signs of sentience in their prey, no matter how obvious those signs are.
I'd read it sometime between 2014 and 2016. I really liked the story and have searched for it online a couple of times since, but haven't been able to find it even though I remember many of the details :( Does it ring a bell for anyone here?