Also known as: 同一CP, 水仙(同人用语), 自攻自受, 自分姦
A romantic or sexual relationship between two different versions or copies of the same character. Most commonly seen between a character and their Genderswapped counterpart, Clone, or Dual Personae.
For non-sexual self-admiration, use Narcissism. When the original character doesn't participate, but two of their alternate versions does, see Selfcest Without Self.