Truman Capote and Gore Vidal were two American writers who had a long-standing feud with each other. The feud began when Capote wrote an article for Esquire magazine in which he claimed that Vidal had been thrown out of the White House after making a pass at a member of President Kennedy's family². Vidal took Capote to court for libel, where the two traded insults². After the pair settled out of court, their feud continued – even outliving Capote².
Not a very satisfying answer because it doesn't answer why Capote would slander Vidal in the first place. Indeed the feud existed before the Esquire slander took place so it's incorrect/hallucinatory for Bing Chat to say "The feud began when...".
Oh, and references (2) and (3) seem to be hallucinated and are unrelated to the question and response despite being cited inline. The other ref links are valuable but well then it's just a search engine with more noise.
