discordant couple n. a pair of long-term sexual partners, such as a married couple, in which one is infected with a sexually transmitted disease and the other is not. (source: Double-Tongued Dictionary)
hikikomori n.— «Hikikomori is not a disease. For reasons ranging from bullying to exam failure, some young people are shutting themselves away in their rooms and having as little direct contact with the outside world as possible. Many are...