The steady stream of allegations that Bill Cosby drugged and sexually assaulted women throughout his half-century career in entertainment has already propelled one '70s party drug -- quaaludes, colloquially known as "disco biscuits" – back into the national parlance.

But as his trial date approaches, a court battle is brewing in Montgomery County over Cosby's relationship to another enigmatically named aphrodisiac.

In a motion filed Friday, lawyers for Cosby sought to bar from the proceedings any reference to "Spanish Fly" – a toxic chemical distilled from dried beetle bodies and the subject of one of Cosby's well-worn jokes. Their filing came in response to a government request to put his repeated references to the drug in front of jurors during his trial in June.

But prosecutors, defense lawyers Angela Agrusa and Brian J. McMonagle wrote, just need to lighten up.

"Spanish Fly is a mythical aphrodisiac, not a date-rape drug," their motion said. "Mr. Cosby's comedic references to Spanish Fly are not admissions of anything. They are jokes – fabrications and fictionalized tales recounted to entertain Mr. Cosby's audience. … They have nothing to do with Andrea Constand's allegations."

They threatened to call an expert witness to explain the difference between humor and reality should prosecutors be allowed to put Cosby's comedy on trial.

Throughout his career, in stand-up routines, books, and TV interviews, Cosby frequently rolled out a bit about using Spanish Fly to seduce women. The drug, he joked in a 1991 interview with Larry King, was perhaps the only chance he had as a teenager to persuade women to sleep with him.

In his book Childhood, published the same year, Cosby recounted secretly sprinkling the substance on cookies he gave to girls at a party when they were 13. He jokingly described the drug as "an aphrodisiac so potent that it could have made Lena Horne surrender to Fat Albert."

Clearly, the defense lawyers said Friday, prosecutors didn't get the joke. "How else would a glamorous movie star 'surrender to' a pre-pubescent boy in Philadelphia?" they wrote.

They accused District Attorney Kevin R. Steele of taking Cosby's humor out of context and ignoring the set-up of the bit – the teenage fantasy of having a miracle drug to woo reluctant lovers.

"This story is about a fantasy, not real life – legends created by the active imaginations of teenaged boys," Agrusa and McMonagel said.

In earlier court filings, Steele argued that Cosby's fixation on "Spanish Fly," alongside his decade-old deposition testimony about using quaaludes with women, proves the entertainer had a more than passing familiarity with date-rape drugs.

"While it would certainly shock the modern social conscience to laugh at, make light of, or joke about drugging and raping women, it is possible [he] may cling to the cloak of comedy to avoid culpability," he wrote.

Cosby, 79, is charged with aggravated indecent assault, allegedly having drugged and molested Constand at his Cheltenham residence in 2004. Judge Steven T. O'Neill is allowing testimony by only one of the 13 other Cosby accusers prosecutors sought to bring in as witnesses to bolster Constand's claims.

The judge has also ruled that Cosby's 2005 deposition in a civil suit Constand filed against him can be used as evidence -- although Cosby's legal team is now seeking to limit its use, including references he made to using quaaludes in past sexual encounters with women. Prosecutors also sought Friday to bar the defense from asking about Constand's sexual past.

O'Neill is scheduled to hear arguments about those and other pretrial issues at a hearing in Norristown on Monday.