Stick to your guns (my husband's catch phrase). If you do not condone irresponsible drinking and want your son to understand that getting drunk is unacceptable, then you are doing the right thing by leaving before things get out of hand. Five-year olds definitely pick up on slurred speech and drunken behavior. Now is the age to begin talking about responsible drinking. If the questions about alcohol have not begun yet, they will shortly. Alcoholics and people who drink until drunk are not necessarily bad people, but they may exhibit behaviors that we don't want our children exposed to and again, your choice to leave is perfectly proper.