Sexual Terminology
Latin is an exact language for obscene acts, such as pedicabo and irrumabo, which appear in the first and last lines of the poem. The term pedicare is a transitive verb, meaning to "insert one's penis into another person's anus", and derives from an analogous Greek word, παιδικω, itself derived ultimately from the Greek word παις, παιδος (child). The term cinaedus in line 2 refers to the "bottom" person in that act, i.e., the one being penetrated. The term irrumare is likewise a transitive verb, meaning to "insert one's penis into another person's mouth for suckling", and derives from the Latin word, ruma meaning "teat". A male who suckles a penis is denoted as a fellator or, equivalently, a pathicus (line 2). Catullus neither confirms nor denies the claim of Aurelius and Furius that he is "not a man", since sexual slang "irrumare" and "pedicare" while having sexual slang meaning of homosexuality, could also mean as little as "go to hell".
Read more about this topic: Catullus 16