Suspension of Disbelief in the Age of the Parody

A week ago a friend of mine watched Indiana Jones and the Raiders of the Lost Ark for the first time. During one scene she commented that it was hard to appreciate the movie for the movie's sake after watching "Family Guy."

Tonight I watched Shakespeare's Julius Caesar. It was the first time I'd seen it performed live, though not my first time through the work. At one very serious line I had an extreme urge to start giggling, imagining ears being thrown at the stage.

In both these cases the observers were unable to maintain a suspension of disbelief, but it was not the fault of the material itself. It was the fault of the parody. The maintenance of the suspension of disbelief in the audience is crucial to any undertaking in the performing arts. Performer and audience have an agreement. As long as a minimum of criteria are met, the audience will suspend disbelief, and the actor must meet those criteria for disbelief to be maintained.

However, with famous lines that have been parodied, that disbelief can be broken much more easily. I am certainly not suggesting that we avoid parodies, but I do have a question:

What do we need in order to suspend disbelief while watching something that has well-known parodies?