someone who would only have sex with themselves.

A person so self-involved, he/she lacks sexual interest in either gender.

An individual that prefers sexual intercourse with one's self..

No to be confused with masturbation. This individual would be a hermaphrodite or male that was exceptionally endowed for self penetration.

The process would most likely be achieved through bending a not full erection back towards the perineum or abdomen for penetration.

To love one's self. Self love.