Yee. Spoilers.

Joseph fathered Josuke when he was older. Josuke is younger because Joseph was already a Grandfather when he had Josuke.

@Ya Boi D7O It is pointless to give me spoilers since I am in part 5: Golden wind

"Joseph fathered Josuke when he was older." who is this "he"? Josuke or Joseph?

"Josuke is younger because Joseph was already a Grandfather when he had Josuke."

So does it mean that he had Jotaro first??

What no Holly cujo did his daughter

First off, my apologies to Ya Boi D20, they meant to ping me, not you. Sorry.

As for the explanation, Joseph Joestar and Suzie Q gave birth to Holy Kujo. Holy Kujo grew up and gave birth to Jotaro Kujo. Joseph is Jotaro's Grandfather. While in Japan one year for business, about 5 years before Stardust Crusaders I believe, Joseph Joestar met Josuke's mom, and he had a troublesome affair, cheating on Suzie Q. This produced Josuke who was born just a few years before Stardust Crusaders.

Joseph Joestar was already an old man, and a Grandfather to Jotaro Kujo, when Josuke was born.

Look at the Joestar family tree. Josuke and Holly are half siblings

Spoiler warning to whomever may be reading this.

A bit before Stardust crusaders, Joseph met Tomoko (Josuke's Mom) and they had a bit of an affair, which led to Josuke, and since this is well after, Joseph and Suzi Q had Holy, like, 41 years after Holy was born. (Assuming my math was right.) and due to this, Holy and Josuke are half-siblings, making Jotaro, Josuke's half-nephew, regardless of age difference.

Though, Suzi Q still forgave Joseph and they're still together. and alive surprisingly. (in their universe that is.)

@Dbr231 So Joseph met Tomoko then cheated on her for another woman which led to Jotaro and Holly. Then he remarried Tomoko and got Josuke. Got it

No it's literally at the ending of part 2 he married Susie q then he cheated on her with Tomoko😭🙏

Did you actually WATCH Part 1 and 2? No offense of course, but I'm genuinely curious.

^^^How

How did you derive this from what they told you?

Are you a troll?