"I Take the Twenty-First"

If people ask you to say things you don't want to say, you can colloquially respond, "I take the Fifth" (referring to the Fifth Amendment's privilege against self-incrimination). So if people tell you not to take that next drink, you should say, "I take the Twenty-First."

(To be sure, sometimes you really shouldn't take that next drink. But then again, sometimes you shouldn't be taking the Fifth, either.)