Walk in a crooked line
Let’s face it, walking in a straight line is something people now practice. Make the line crooked and you’ll quickly have people staggering like drunken zombies, regardless of the number of drinks they’ve had.
Not buy a kebab
Somewhere between the pub and home there is always a kebab store. If someone can walk past it and not buy a kebab, then they are sober.
Discuss politics without yelling
Although this may just mean the person yelling is a politician. Either way, just lock them up to be on the safe side.
Not heckle a comedian
Unless they are on this list, in which case don’t stop at heckling, molotov invented a drink that needs to be served to them.
Check that they don’t use the phrase “I’m not drunk.”
May be combined with the phrases “I’ve only had one/couple of drinks” or “Just a wine with dinner.”
Refuse to sing karaoke
Much like the kebab, there is no way a drunk person can refrain from busting out a classic tune in all its warbling, tone deaf, shouted glory.