Slang consists of words that are non-standard in a given language and is generally spoken to show inclusion in a specific social group. When you translate slang, it is particularly important to know the culture to understand how to translate them correctly without ruining the text, or even worse, changing the intention of the author.
This is a prime example of how knowing a second language is not enough for some industries. If you do not understand the phrases such as “lit, crib, gimme, bae, unfriend” and you translate the phrase verbatim, your sentence will make no sense. Slang tends to be opaque and resist translation –insiders best understand it and thus it looks inward as if to protect the member of a language group from snooping ears.
Parody and satire are viewed as a means by which a society reveals its underbelly to itself –and potentially to outsiders. The whole point of satire is to be revealing, albeit in an artistic way. Thus it is more transparent, even when it employs references to what later (German) translation theorists dubbed culturally sensitive units. This type of text tends to expose if translators are indeed bi-cultural or not.
On the other hand, if you accurately translate the slang in a document, audio, video, etc., you make the reader/viewer feel at home. It is very welcoming to be reading/watching a foreign book/film and be able to connect in such a way where you do not even feel the language barrier.
That is the intention of the translation, to give a natural feeling of the language and culture. If you are ever in doubt or need help, please feel free to call me. My job is to assist you and free you from all these slang headaches.