I don't really know how to explain this well, so I'm just going to lay everything out as ask for advice.
I'm 23, male, and straight. I didn't have a traumatic childhood, but I spent a lot of time alone, and I made an imaginary friend to keep me company. 15 years later and she is still with me, but over the years she has developed into a separate personality....sort of. We truly care about each other and act as brother and sister, but we know it's not a normal situation and are worried about the implications. Do you guys, as objective outsider have any advice?