I think we're missing some stuff here
Many of the classic Greek Playwrights wrote in "Shakespearean" forms full of bawdy jokes. One of Aristophanes' plays - Lysistrata from 411 BCE - concerns a sex-strike by the Spartan wives, and many jokes where the Athenians accuse the Spartan men of carrying spears hidden under their cloaks.
<a href="http://en.wikipedia.org/wiki/Lysistrata".Wikipedia entry
Aristophanes wrote in 425 to 388 BCE, so his Jokes are well in the time frame indicated. it's just that they have a veneer of "clasicism" that hides the bawdy core of the humour.
Shakespeare wasn't vulgar, was he?
