An emotion mask is something referenced my Spade while taking about reading people better, as described Spade said "Everyone wears a mask, the mask they chose will affect the rest of their life, some people get lucky and pick a good one, others aren't as fortunate. Not all masks are unintentional, some people choose one to hide their real feelings. Although it is possible to crack an emotion mask it's very hard, only the owner of the mask can choose to take it off"
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