Former first son Hunter Biden defied first lady Melania Trump’s demand to apologize for “defamatory” statements alleging a relationship with convicted sex offender Jeffrey Epstein, setting up a legal battle.

In an interview with YouTuber Andrew Callaghan on his web series Channel 5 earlier this month, the former first son repeated a false claim that Epstein introduced Trump to her future husband, first alleged in an audio clip from Epstein shared by the Daily Beast. The first lady sent a letter to Biden through her lawyer, Alejandro Brito, demanding a retraction and apology, or else she would sue for $1 billion. Biden responded bluntly and crudely.