This poem is Catullus, one of the most obscene poets in history, and it's most certainly not intended to be taken literally!

The poem you quote is a famous example of satirical poetry intended to mock its target: just pure abuse, and has no factual component whatsoever.

It’s probably Catullus’ second most famous poem, after Pēdīcābō ego vōs et irrumābō (NSFW text at that link).