Do you:
a) Throw him out of the bar and let him vomit in the street?
b) Join him in the bar, drink, and sink baudy songs all night?
c) Take him home and tuck him into bed to sleep it off?
d) Take him to detox and get him to change his ways?
e) Ask him to start a business with you, putting pink elephants on people's lawns to celebrate various things?
Feel free to add your own suggestions.