Arphocras hic cum Drauca bene futuit denario.
I looked it up on the web. The more or less accepted translation goes like this: Here Harpocras has had a good fuck with Drauca for a denarius.
But I sent the line to Jacob to see what he thought. He wrote back: Something along the lines of…Here Arphocras laid well with Drauca (my dictionary says this means sodomite, but it is a capital D so I made it a name. I think it is a pun.) for a silver coin. Basically… “Arphocras fucked the shit out of some male hooker right here for like no money.”
Then I looked up the quotation in Craig A. Williams Roman Homosexuality. Apparently, the price paid to Drauca was eight times the going rate (according to other notations on the wall).
The plot thickens.