Rogue Roman by Lance Horner (Pan, 1970)

Found on a dusty shelf in the Green Shed:

 

Imperial Rome--centre of the world--throbbing with the white heat of violence, bloodshed and uninhibited sexuality...

Bought as an actor, kidnapped by pirates, sold as a gladiator, young Cleon's beauty and flagrant masculinity made every woman--harlots and Vestal Virgins alike--desire him.

And passion drives Cleon to help destroy a Caesar who combined the vices of his predecessors with his own special perversions--the Emperor Nero.

Soft-core sixties smut, with a plot revolving around a hero whose main attribute is... the size of his, um, main attribute:

Contux took a firmer grip on the cloth and yanked.  There was a ripping sound and the hand came away with the front of Cleon's tunic clutched in the swollen fingers...  "I take it back.  He's more than a man - he's a true stallion.  He was shouting the words and waving the cloth for all to see.

(Page 125) 

Why am I suddenly reminded of Biggus Dickus?