If harry and dudley stay on クリスマス card terms, do aunt ペチュニア and uncle vernon ever die?

uh....

wtf does one have to do with the other? o_O

Well, I don't think Dudley's going to live with his parents his whole life, so it's not so weird he's on クリスマス card terms with him, and not with them. I don't think it means they actually died.