Sinhalese is an Indo-Aryan language and exhibits a marked diglossia between the spoken and written forms.
As such, it is also difficult to find instances of colloquial slang in any form of formal literature.
They are not found in any form of media, publications; not even popular websites show them, apart from unmoderated blogs and talk pages.
For example, Āyis Ammā (ආයිස් අම්මා) is a slang term used by certain parts of Sri Lankan society to express pleasurable surprise (similar to wow!).
For example Kuppiyə (කුප්පිය) which literally means 'small bottle' or 'small lamp' is used to refer to an informal tuition class conducted by a student, for a small study group free of charge.
However they also make great effort to avoid kārəyā when they speak in a formal venue.
This slang, however is well accepted in the mainstream diglossia, unlike other blasphemy terms discussed above.
For the purpose of swearing (for fun, and as nicknames), it is a common practice in many languages/cultures to equate people with animals; and Sinhalese is no exception.
This type of sexual slang ranges from "mild" to "severe" and sometimes borders the "extreme taboo".
These terms are collectively called කුණු හරුප (kuṇu harupa) in Sinhalese which literally means 'dirty/rotten utterings'.