I am implying such a relationship should never exist due to the blood connection. And it would be foolish to be true love.
Oh okay its the blood connection!!
So lets say at the age of 40, you are finanically successful and single. Own your own house, good career, ect. You decide that you want a young girlfriend, maybe around the age of 18.
You find this girl, start dating, fall in love, get married, ect.
At some point after all this, you both decide you want children. You go to a fertility doctor to make sure everything is in order.. The doctor comes back with surprising news.
Turns out, one of the girls freshmen year in college you dicked got preggers. She never knew who you were as you went out of town for that party. Everyone was drunk ect. She decided to keep the baby and take on single motherhood. This child is now your wife.
So what about the blood exactly prevents these types of relationships from existing? Your arguments are not logically sound.