Group of people start a drinking game and a sober person/nondrinker is invited to join without all other players knowing they don't drink.
Should they play?
Heard some mixed stuff on this but mainly that they shouldn't because a lot of drinking games lead to confessions which the drinkers will forget and being sober is unfair as they will remember. Being a nondrinker in a drinking game isn't half as fun though and unless they're dickheads then they're probably just joining in to be social, not for future blackmailing uses.
Opinions?