Someone who acts as the leader of the group, without having any votes to assign them to that position. They are the ones who keep the group together and makes all the difficult decisions.
James: So who is the leader of the Mystery Club?
Calvin: While nobody put it up for vote, David is the one who acts as the de facto leader of the group.
Boys who enjoy yaoi (a genre in Japan that contains sexual and/or romantic relations between two men); literally translates to "rotten boy"; corresponding female : fujoshi