Lyrics:

You have any kids?
Yes, I have one daughter, how about you?
How many baby daddies do you have, if you don't mind me asking?
Ellipsis
I have one daughter (she has one daughter)
I understand, and is she by the same father? (Is her daughter by the same father?)
I have one daughter (again, she only has one daughter)
I understand, and is she by the same father? (This guy is good at maths)
I don't understand