Coincidentally, I came across a review by Michael Hinds of The FBI’s Obscene File: J. Edgar Hoover and the Bureau’s Crusade Against Smut, in which Hinds begins with a poem by Catullus.
The comparison between the “obscene” Bukowski and the “obscene” Catullus is too good to pass up.
listen, I told her,
why don’t you stick your tongue
no, she said.
well, I said, if I stick my tongue
up your ass first
then will you stick your tongue
all right, she said.
I got my head down there
and looked around,
opened a section,
then moved my tongue forward…
not there, she said,
o, hahaha, not there, that’s not
the right place!
you women have more holes than
I don’t want you
well, then I’ll have to do it
back and then at the next party
you’ll tell people I licked your ass
with my tongue.
suppose I promise not to
you’ll get drunk, you’ll
o.k., I said, roll over,
I’ll stick it in the
she rolled over and I stuck my tongue
in that other place.
we were in love
we were in love
except with what I said at
and we were not in love
with each other’s
she wants me to write a love poem
but I think if people
can’t love each other’s
and farts and shits and terrible parts
just like they love
the good parts,
that ain’t complete love.
so as far as love poems go
as far as we have gone,
this poem will have to
– Charles Bukowski
published in Madrona, No. 2 
Listen to Buk reading the poem at City Lights Poets Theater, San Francisco .
And here’s Catullus two millenia ago, in a translation I prefer to Hinds’s:
So help me god, I can’t tell the difference
whether I sniff at Aemilius’ mouth or at his ass.
The one is not cleaner and the other not dirtier.
Actually the asshole may be cleaner and nicer in the end,
at least it has no teeth, the mouth has long fang ones,
with the gums of an old manure-loaded shit wagon,
and a foul odor which the pissing cunt
of a mule in heat is often likely to have.
Well, he fancies himself a beauty, fucks many a lady
yet is not sent to the mill-jail as a working ass.
If any girl touches him, wouldn’t we think her ready
to lick the ass of a sick torture-chamber executioner ?
– translated by William Harris
Anyone out there have suggestions for other comparative obscenities?