John Mulaney and Olivia Munn are dating, a source tells ET. ET has reached out to reps for Mulaney and Munn for comment. The news comes days after ET confirmed on Monday that Mulaney and his wife, Anna Marie Tendler, had split after six years of marriage. «I am heartbroken that John has decided to end our marriage,» Tendler said in a statement to at the time.