16
Don't know what it might be for certain. Sun squaring Neptune might indicate a "missing father", in the sense of vagueness, inconsistent fathering, maybe. Opposition or squaring of the two may show an exaggerated conflict of outlooks or opinions between the father and child. (not that a given amount is natural, but my father was cool with most of the other sibling's dreams and expectations they had in life. As for mine ...NOT! LOL)

I was the only one with this aspect out of the eight children. Maybe inconsistent fathering once more. The only squaring planets in my chart I have are planets in a square with my luminaries. Moon with Saturn I consider overstrict/ smother mother maybe.

I have the Sun/Neptune square at close exactness and I had that type of relationship with my father definitely. Ranging from periods of just simply misunderstanding one another and letting it get blown out of proportion with him, and longer times of him not giving a rat's *** if he was involved in my life or not.

He certainly was a man with a western hemisphere heavy chart ...always focused on his social life and standing (what others thought to a degree). I worry about that with my chart being western heavy if I would have had children, but I learned that they are more important than society to a degree from seeing my father's lack of that realization. My former spouse had Sun square Neptune also and had about the same identical problems. My Relation with my mother was about the same as the Moon square Saturn relationship.

My other luminary square. All of this is somewhat speculation of course. Planets squaring and to a lesser degree, opposition with the Luminaries are exceptionally difficult challenges to master. Since both of them are naturally the most powerful planets we experience. As is most parents or parent figures are the most powerful entities in our existence during the formative years obviously.

17
Astrology can be as complicated or as simple as we make it. Like Eve Dembowski says in the latest the Oraculos podcast it is a language to communicate with divinity we set the terms divinity understands how we use the language to communicate . We can use harmonics progressions different terms or listen to intuition, It is a form of magic.
So in answer to the original question I set where is the father ? In my chart my biological father is the 4th house ruler & he is in my 3rd house. My step father is the ruler of the ninth house in Gemini on the MC