In "Damien", he was at the bar laughing with Mr. McDonald, using their sons' "That's gay!" catch phrase. He shares the same characteristics as his son, with the exception of the turquoise shirt; he wears a purple shirt which resembles that of Fosse's.
His appearance is similar to his son's, the only difference being his shirt; he wears a purple shirt rather than a turquoise one.
Much like his son, he likes to call things "gay" whilst laughing in a deep voice.
http://www.imdb.com/title/tt0705919/"South Park" Damien (TV Episode 1998)