Hilchos Lashon Hara, chapter 1, section 5

It makes no difference whether a person speaks lashon hara on their own, or someone else keeps pushing until they finally speak. Either way, it is forbidden.

Even if a father or a rav – people one must treat with awe – asks a person to tell them about something, and the person knows that the story includes lashon hara, or even "the dust of lashon hara" (a hint of it), they must not do what was asked.