People that are in an Christian Singles intimate relationship with one another are often called a couple, especially if the members of that couple have ascribed some degree of permanency to their relationship. Such couples often provide the emotional security that is necessary for them to accomplish other tasks, particularly forms of labor/work.
When used by a boy or man about another male in a non-sexual, non-romantic context, especially when it's a friendship between a girl and a boy, they use the term "guy friend" so it would avoid confusion with the sexual or romantic meaning.
