Reunion was a game played on the American edition of Whose Line.
Similar to Three Of A Kind, Reunion involved three performers meeting at a reunion for an unusual profession. They had to greet each other in the style of that profession and then perform their "old song", all singing in one voice.
One version of this game featured Ryan Stiles, Colin Mochrie and Greg Proops meeting at a reunion of army drill sergeants. Ryan, who arrived late, attempted to use a training call of "Who's the guy who's always late?", only to have Colin and Greg respond very differently.