When teaching universal ethics vs cultural relativism to my Riga Business School students ten years ago I used my marital track record to debate gay marriage, about which many said never in Latvia. Quoting a Graham Greene novel's characters:

-"Love is a game, marriage is a game."

-"No, you idiot, sex is the game, marriage is the penalty."

They all laughed, after which I said, "you all know my marital track record. Clearly gays are playing the game without paying the penalty. It's not fair."

Then those who most loudly objected to gay marriage laughed even harder. When I asked them why it was funny, they had to actually think about why they laughed and reflect on their objections to gay marriage. Humor is a far better teacher than direct intellectual confrontation, and failure the source of genius.