May have been part of a sci-fi war collection. The narrator is an alien itself, I think, and is part of a rebellion to overthrow human oppressors, but then is horrified that his fellow aliens have developed a taste for the same drink.
“We Who Stole the Dream”
This story, by Alice Sheldon (pseudonym James Tiptree Jr.) has been published in these collections.
From a description here, we see that humans harvest the "tears" of an alien species:
One race sweated a chemical when frightened or in pain that to us is a very strong intoxicant. We have developed a ruthless industry of capturing these creatures and torturing them to death so that we can capture the chemical as they excrete it during the torture sessions. In fact, human beings try to capture mated pairs because when the creatures watch their loved ones tortured to death it increases the yield and potency of the chemical. The drink is called Star Tears.
Later, members of this species encounter other Joilani drinking the same ill-gotten beverage.
They began to fear what their cousins would do, until they watch fellow Joilani drinking Star Tears, and then know for sure that this race was no different than the humans from whom they had escaped.