The Twilight Zone
The plot reminds me of that episode of "The Twilight Zone" where a writer is "cheating" on his wife with another woman, but it turns out he just invented the other woman by writing out her description, and then it turns out he invented his first wife in the same way, only he got tired of her. (And then it turns out he invented Rod Serling, but that seems unlikely to happen in this film.)
Is this film supposed to be based off of that? I know the idea of a writer creating real people from his imagination is not an entirely original plot; anyone could have come up with it. But I was just wondering.