Thank you so much for your response, Majestic, Buntaro and mdchachi.
"The intended audience/reader" is probably the word I should use, as suggested. Also thank you for correcting my grammatical mistakes. It's so helpful.
So it sounds like you don't say, "誰によんでもらいたいんだろう" or if you say this, it doesn't sound natural?
Let me give you another situation.
You are writing a story about your family. During your writing, you are suddenly not sure what you are doing. You feel you are just wasting your time, writing the junk which no one would read. You ask yourself what you really want. "Do I really want to write this? Why do I want this story? If I complete this story, who would I want to read?" Probably, you want your father to read the story most.
The last question above is my question.
Or when you ask yourself in your mind, "誰に食べてもらいたいんだろう" during your cooking, how do you say it? Probably you just say, "Who do I want to give this meal?" ?
There might be no exact translation for this expression...
As an English leaner, both American and British English are English for me. I would like to learn both.
Thank you.