Last weekend the acclaimed author celebrated Ireland's vote to back gay marriage and responded to a fan who proposed a wedding between her character, Hogwarts headmaster and "Lords of the Rings" wizard Gandalf, reported Daily Mirror.
But the controversial church, based in the US, wasted no time in threatening to picket the marriage between two fictional fantasy characters.
They wrote, "@jkrowling wants Dumbledore and Gandalf to marry in Ireland; if it happens WBC will picket! #notbanned," beside a poster displaying homophobic messages.
Rowling is a vocal supporter of gay rights and in March responded to a Twitter user who said she could not see Dumbledore as gay.
Dumbledore was revealed as gay by Rowling in 2007, where she said of the headmaster of Hogwarts was in love with his rival Grindlewald.
