King Charles Hates Soccer, Prince William Reveals to Kelce Brothers

Prince William made a surprise appearance on Travis and Jason Kelce's podcast this week ... and he dropped a bombshell about his father, King Charles.

William joined the brothers on "New Heights" ... and among the many topics -- no, nothing about the wedding! -- they talked soccer, since the World Cup is happening ... and that's when PW made a shocking admission -- the King "hates" soccer!

William, of course, is a huge fan -- and he said it was hard not to be since in his youth, that's pretty much all kids talked about ... but yeah -- the King ain't having it.

The heir to the throne didn't say why his dad has such resentment for the game that you would think he, of all people, would love -- but there you go.

And again, for fans hoping some Taylor Swift wedding deets were spilled on the episode that dropped the same day as the big event ... they were not.