That slut who does you, Gongylion: what's she saying? I don't mean your girl; I mean your tongue.
What's this about? The Latin runs:
Quid narrat tua moecha? Non puellam
dixi, Gongylion. Quid ergo? linguam.
I think I know what's going on here, but I could be wrong; I don't know of anyone proposing this reading before.
Here are a couple of older versions, courtesy of the Bohn Classical Library version of the late 19th century, which cobbled together existing translations by divers hands:
What says your trollop, Tongilion? I do not mean your trull. "What then?" Your tongue.
What does your strumpet say, Tongilion? I do not mean your wench. "What then?" Your tongue.
'Tongilion' was the upshot of a German journal article of 1846; the MSS had Congylion or Goncylion. Shackleton Bailey's Loeb settles on 'Gongylion' and I think this must be right, although my reading of the joke is quite unlike his. For S-B, the poem means:
“What does your wife’s female lover have to tell?” I was not referring to a girl, Gongylion. What then? Your tongue.
'Tongue' (lingua), you see, is grammatically a feminine noun. Moecha is 'adulteress', more or less. But is Gongylion the husband?
Translators typically assume Martial's addressee, 'Gongylion', is male. The name is clearly Greek either way. Certainly one finds masculine names in '-ion', such as the 'Masclion' of Martial 5.12. But we also find women's names in '-ion', often in an erotic context, such as the Klonarion of Lucian's Dialogues of the Courtesans 5 -- and there are especially strong reasons to prefer one here. 'Gongyla' is a name from Sappho's poetry, famously so. See it carved into her seat in the schoolroom of Lawrence-Alma-Tadema's Sappho and Alcaeus of 1881, just to the left of the standing girl's yellow garland. This invites a reading in which non-normative female sexuality is to the fore.
By my reading, Martial's addressee is female. Line 1 sets up the expectation that Gongylion's moecha is a lesbian paramour; line 2's big reveal is that she herself is her own expert lover.
I would like to think my interpretation stretches the text less -- even as it requires prodigious flexibility of its autocunnilinctrix. And shouldn't that be a word?