- Description: Sex between two different versions of the same person. Usually between someone and their genderbent counterpart.
- Notes: Not to be confused with twins.
- Gender: If the selfcest-sex only consists of one gender, add it to that respective namespace; futanari and shemale both count as female. If the group has more than one gender use female:selfcest.
- Japanese: 同一CP
- Slave Tags: Female, Male - with notable synonym selfsex.