Romantic and/or sexual attraction to couples. The root word symbio (from the Greek word symbiosis, meaning the shared
relationship between two living things) is paired with sexual to mean an experience of attraction to the
relationship and/or energy shared between two beings.
The term can be used as an
alternative for, or addition to, the term "unicorn", which typically describes (sometimes in derogatory or objectified way) a "mythically rare" bisexual woman who is willing to have sex with, or date, a couple.
Symbiosexual describes ANY person who experiences attraction to couples. For some, it may be used as an identity label to describe their sexual orientation.