Could be wrong but I think the paternity test has already been taken. Think I recall Hunter complaining he wanted $ amount lowered.
https://people.com/politics/hunter-biden-confirmed-paternity-test-fathered-arkansas-child/
So it looks like there WAS a DNA Paternity test, and HUNTER is the father, so this makes him indeed a double SCUM BAG. Poor child. And the grandfather a TRIPLE scum bag.