Even the EU is going to have some legal standards around this sort of thing, or you could spin whatever you want into being some sort of coded language for something that is illegal. I'm unfamiliar with EU (or Germany as it may be?) standards, but using the US as an example, there's the Miller Test [1] for determining obscenity. It has three parts:
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1) Whether "the average person, applying contemporary community standards", would find that the work, taken as a whole, appeals to the prurient interest
2) Whether the work depicts or describes, in a patently offensive way, sexual conduct or excretory functions specifically defined by applicable state law
3) Whether the work, taken as a whole, lacks serious literary, artistic, political, or scientific value.
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Something can only be deemed obscene if it meets all 3 criteria, which courts tend to interpret pretty rigidly. For instance, an average person is not the most sensitive or politically correct person. Of course it also somewhat amusingly emphasizes the cultural differences. Creative use of a nipple and some mayonnaise might be deemed as obscenity, while a graphic decapitation could not.
[1] - https://en.wikipedia.org/wiki/Miller_test
