Idk if anyone here still believes it, but some people on other sites still do.
People really believe that Oda will reveal in an SBS that Harald and Xebec actually cheated on Ida/Eris (who they loved dearly) with some random hoes to produce Kaido and Buggy.
Yeah, that one genuinely baffles me. Like, the Harald theory literally only exists because someone thought his framed picture in the castle looked kinda like Kaido. Lol.
It should have been laid to rest when we found out Harald fell madly in love with one woman 100 years before Kaido was even born, and the ONLY other woman he was ever with was reluctantly, due to Elbaf politics. Harald just wasn't the type of guy to sleep around. Hell, given he was crying at his wife's funeral, he probably even grew attached and came to love HER over time (even if likely nowhere near as much as Ida). Nothing about the guy was casual about romance.
Pretty sure the only guy who canonically cheats on his wife (and could potentially be the farher of who knows how many random characters) that we know of is fucking Rayleigh. And she is weirdly cool with it. Lmao.