adding another deadbolt to my door

So how do you guys handle it when some stranger (or even friend) says something bigoted around you? This can range from the n-word to gay-bashing to sexism.

Not that I'm above tweaking these groups myself, but it's always affectionately and to friends who are members. Do I call gays "prancing Nancies?" No. I just call Mike that. And then he rips me back. It's what we do. He is my pink d'Andre.

No, I'm not talking about un-PC banter amongst friends. I'm talking about sitting next to a white old fart on the plane who groans, with the gravity of a man in the same beleaguered foxhole as me, "I ain't ever had a lady pilot before."

"I have," I said, obviously mocking him. "It was horrific." He nodded as though I needn't have added that part. It was a given. "I'm, um, kidding," I felt compelled to add.

What do you do in this circumstance? Humor them in silence? Tell 'em to shut up? Treat it as a learning opportunity, the ultimate act of hubris with a man clearly determined to learn nothing in his 70 years on earth?