Lyle_Dayek said: Hm. If you have sex with a female version of yourself, is it incest? Or masterbation?
Personally I call it self-cest. otherwise if they masturbate then its the same word to describe two different things. But its still weird and horribly strange to even think about that
If its the same timeline but you have encountered your opposite-gender duplicate via time travel, then s/he is still technically you and thus it is masturbation. If s/he is the product of a divergent timeline or alternate universe, s/he is not technically you as s/he occupies a different position in time and space to yours, so it is incest.
In both cases it is incredibly weird for all involved.