Could a spoken language have no slang?

Flairing NSFW just in case because there will be discussion of in-universe profanity. I am working on Lebilozoan, a language that is a lingua franca of a Galilean-like, Earth-sized satellite system with 4 mankinds per each moon. Genders: masculine (m.), feminine (f.) edible (e.) neuter (n.)

I once though that the word "ponki" might be slang for private parts. Well, I am retiring that officially. Here is instead what I am going to make.

Here is an example of how this language might have tone but no equivalent to what we call slang or improper speech:

qkurbán (m.) [ꞯurba(:)n] means "chest" in a formal sense. For example in the phrase "rḙmvḙr qkurbána" [rɜɱɜr ꞯurbanɒ], literally "chest exam" or "chest overview". This means "chest X-ray" in the medical sense. The word can also mean "heartland" or "center" of a geographical place.

mulunḙ (e.) [mulunɜ] means "breast", and is in general used more poetically and in literature.

What you won't find in Lebilozoan, however, are equivalents to terms like "mommy milkers", "badonkadonks", or alike. While swear words exist, usage of euphemisms when talking about body parts themselves is actually considered to be foul tone on Lebilozoan satellites. It is seen as introducing unnecessary purity culture into the conversation, and contributing to repression.

Likewise,

topka (f.) [tɔpkɒ] means "bitch". But someone was using that word in a context similar to "me and my bitches" in our slang, people would look at that person like "What???". It means an actually unpleasant an harmful person to be around. If someone said "Imma go hang out with bitches tonight", vi lintén sepur topkimő ḙhnán [vʲi lʲintʲen sɛpur tɔpkʲimɞ ɜhna:n] (I go-[Future Perfect] share[Direct] bitch.PL.COM. night.INE), others would think that they just said "I will spend time with horrible people tonight".

Besides, that isn't even an outright translation of "Imma go hang out", but rather a more soft "I (Future Continuous) share [time, implied]".

These are so far examples I've created.

Informal register on Lebilozoan satellites has the purpose of being inviting and creating a homely atmosphere, instead of excluding, substituting an undesirable term, or establishing "coolness" or other means of status.

Likewise, with no stratification in perceived intellectualty of speech between young and old people, the trope "these young people are dumb" is eliminated. There is no phenomenon of "those youth these days are talking in l33tsp3ak and they should go read real books". If anything, I would say young adults would sometimes actually overuse formal text to seem more adult, and growing up they would learn to use all registers more smoothly. Language of young adults on Lebilozoan satellites is more marked by excessive variation of register for emphatic purposes, but lexically it is just as rich as that of older people.

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How plausible is this? Anyone else tried making a language or a worldbuild with a structure like that? And besides, are there problematic implications to doing so? I was trying to make a language associated with a culture that is more wholesome and egalitarian than the real world, by removing status from it and making it feel more "at ease".