You suspect a passenger has had too much alcohol, but they are still demanding another drink. How would you manage it?

If I suspected a passenger had too much alcohol but was demanding another drink, I would refuse service calmly and clearly. I would say something like, "For your safety, I am not able to serve another alcoholic drink right now, but I can bring you water or something non-alcoholic."

I would avoid sounding judgmental or embarrassed, because that usually makes people more defensive. At the same time, I would treat it as a safety issue, not a customer preference issue. I would alert the rest of the crew so everyone gives the same answer and the passenger cannot shop around for a different response.