Oscar-winning actor William Hurt exploded in anger at his palimony trial Tuesday when a lawyer for his former lover made a crude joke about their son. Hurt declared that his memory was "blocked" by the insult, and the judge called a temporary halt to the trial that began Monday at state Supreme Court in Manhattan. "I'm blocked! What you just said is an insult to me. You understand? O.K.? I can't hear anything else. I can't hear anything," snapped Hurt, 39. Hurt completed his testimony Tuesday and was replaced on the witness stand by former ballerina Sandra Jennings, the mother of Hurt's son, Alexander, 6, who is seeking half of Hurt's $10 million in earnings. Lawyer Richard Golub, who represents Jennings, had earlier complained that repeated objections by Hurt's attorney had interrupted the rhythm of his questioning. "You know rhythm is everything," Golub quipped in promising the judge that he would soon finish his questioning. "Get your rhythm right," Hurt sneered, touching off laughter in the courtroom. "You had yours right, pal, when you had Alex, didn't you?" Golub retorted, stunning the courtroom into silence. Hurt asked the judge, "You can permit that?" Although Hurt's attorney remained silent, the judge answered, "Objection sustained."