Yes they do. I grew up in a stable, so to speak
My dad was embarrassingly hung and also very forgetful. So he could walk around the swimming pool with half his junk out of his speedo or bathing suit without noticing. His balls were the biggest I have ever seen, including in porn. Of course I never saw him hard, but I know he's the biggest my mother has ever had - and she's had a lot, before and after him. His bulge is obscenely big, and he's famous in the family for being horsehung - so was his dad. All the photos with my grand-dad wearing soccer shorts or tight pants, or my father wearing extremely tight trousers in the 70s attest to their surreal endowment.
Both my brothers are hung too. This has been confirmed by ex or current gfs of theirs, as well as by their pals.
My oldest brother's partner calls his cock "the baobab". He let me know several times that he knew how big I was, and that I was even bigger than him. I think he is 8x6.
Our middle brother has bigger balls than my oldest brother - they're similar to mine. His cock is about 7.7x5.9, so I've been told.
I'm the youngest and apparenlty, the biggest.