fiction - How do you reference pop culture in a dialogue without proper attribution?

I'm not sure exactly how to ask this question in a vacuum so I'll give an example first:

Many people are familiar with the Mitch Hedberg joke about an escalator being "temporarily stairs" rather than "broken". You may be in a group of friends that knows his material, so if you come across a broken escalator, someone might make the joke or reference it in some way.

In normal conversation there's no attribution. You'd say "oh look, temporarily stairs", not "well, as Mitch Hedberg said, ...". Conversation is very informal.

So the question then is, how would you do something like this in fictional dialogue, keeping to the spirit of this type of casual conversation without coming across as if you're ripping someone off?

Answer

I'd do it exactly as you've demonstrated, informal without inline attribution. You can then make mention of it in some form of bibliography at the end if you wish, but remember that commonly known phrases don't require attribution, depending on context/audience. It's also possible to include mention of the reference in an "Acknowledgments" section.