Secondly, there is no father. Or mother.
There is nothing for him to care about.
So if the mother (who is mother of nothing by your definition) decides to keep the, shall we say organized mass of desperate cells, since there is no father, he should not think himself responsible for the mobile Petri dish's medical care. Nor, since he is not a father, should he feel in any way responsible for the "mass". And it is OK for him to feel no responsibility for this tumor.
But wait. There comes a day when this tumor is expressed and suddenly it is a) a human with rights the same as yours and I and b) the person who is, suddenly as lightning, now a father, is required to pay for the organized mass of cells until it is 18 years old.
That is beyond absurd. Care to rethink your position?
I actually have no problem with the father, prior to birth, deciding that he does not want a child and formally asking the mother to abort. If she refuses then it is on her. She can raise the child as she pleases. He would have no claim, right or privilege to be in the child's life at all. In fact, if he does demand abortion, he should be restrained from ever seeing the child.
And here lies the reason that trying to make some logical argument when faced with the dilemma of abortion is pointless. Woman want absolute rights to run their lives as they please. They do not want men to have the same rights WRT children.
There is a reason that certain conventions have worked for, oh, say, 100,000 years. Yet we collection of monumental egos believe we should simply ignore that without an alternate plan.
By the way. Since I believe in body integrity, I believe that a person should have the right to refuse the invasive procedure of having blood drawn for any reason. Let me know how that works out for y'all's paternity suit.
I think women are not making their case very well. Feminism is a failing philosophy. That is not to say that feminists do not have some good ideas. It is to say that they are very bad at explaining them and/or selling them politically. So far, other than some vague claim of "fairness" there is little in modern feminism to attract the interest of the greatest majority of men.