"Crocodile tears" is a idiomatic expression of the Portuguese language, used in the sense of "crocodile tears", i.e, someone who pretends to be crying.
Saying that a certain person is crying "crocodile tears" means that they are faking a feeling of sadness.
This expression arose from the observation of the behavior of crocodiles in nature.
These reptiles, when capturing prey, bite it so hard and eat it without chewing, swallowing it whole.
To do this, they need to open their mouths wide, causing their jaw to compress the tear glands, making them tear up. Thus, the crocodile seems to cry whenever it is devouring its prey.
The expression arises from the idea of the crocodile appearing to cry over the death of its prey, when in fact it is just trying to taste it as quickly as possible. Tears are mechanical, that is, with a total absence of emotions or feelings.
A person who cries “crocodile tears” is seen as a hypocrite and a profiteer, as he tries to gain people's trust by doing he says that he cares about other people's problems, as if he were an altruistic individual, when in fact he's just thinking about himself (selfish).
Learn more about the meaning of altruism and selfishness.