Feel like they don't really need to keep a secret since the boss said to just keep it in the company, although some blabbermouth might spread it outside the company heh
With that being said though, If "Love is forbidden" then its pretty weird that it seems like no one knows about it? I mean some might ofcourse, but with how interested people seem in FMC it gives the impression no one knows
The love is forbidden part is actually super common, to the point that even in Apple, if a married couple applies to the company they cannot even be in the same department or team. Still more or less exaggerated here, but not by much
The no love rule in the company seems so shallow. FEMC is literally a chief department and she had no idea either. The idea of restricting relationship in normal workplace is already weird enough, or it's a JP thing.