It's always awkward to discuss drinking habits with a colleague, but never more so than at a sales conference or in some other out‐of‐the‐office business/personal situation. Most large companies have established routines for identifying, warning, and assisting employees who show signs of chronic alcohol or drug abuse, but when a fellow sales rep blows a deal by getting drunk at a client dinner, there's no employee assistance program around to intervene. There's probably little you can do at the time, short of making a scene—and he has probably already taken care of that; so, your goal is to make sure it doesn't happen again. That means changing his behavior—at least in his business meetings with you.
This script can be modified to: