"What'll you have?" He asks.
"Oh, I don't know. Same as you I suppose." She replies.
The husband orders a couple of straight whiskies and throws his down in one gulp. His wife watches him, takes a sip from her glass and immediately spits it out.
"Yuck, it's horrible," she splutters. "I don't know how you can drink this stuff."
"Well, there you go," cries the husband.
Spoiler:

