An interacting population of like-minded individuals, affecting the identity of the given members and also their cohesiveness. In gaining similar social perceptions gives them a sense of solidarity that may or may not lead in the exclusion of other individuals that do not share one or more of their like-mindedness.
Communis comes from a combination of the Latin prefix com- (which means "together") and the word munis probably originally derived from the Etruscan word munis- (meaning "to have the charge of").
The members of that community 'unanimously' agree that things should be kept wholesome within a relationship (minus the making out), but are unaware that one of their number, presumably their leader, has already engaged in oral sex, among other things.
(ALSO, see numbers 1 and 2 of hypocrite)