How are the duke’s actions toward his listener in the poem consistent with the duke’s behavior toward his last duchess? Cite details from “The Last Duchess” to support your answer.

The duke effectively controls his conversation with the Count's emissary completely, just as he attempted to control his last duchess. He talks and talks, and his auditor never has a chance to get a word in edgewise. We only learn who the Duke is actually talking to in the last eight lines of the poem, when he references "The Count" who is the "master" of the man to whom he speaks.
We learn, quite late, that the duke is looking to remarry, as he brings up the subject of a dowry. He seems to have begun speaking with little to no prompting, and he goes on and on about his last duchess, his problems with her personality, and even what he did to resolve those problems. He controls her completely now, as her lifelike portrait is hidden by a "curtain" that "none puts by" except for the duke; he gets to decide who sees her face with its nearly ever-present "spot / Of joy." In her life, the duke was unable to control her, and it angered him that "she ranked / [His] gift of a nine-hundred-years-old name / With anybody's gift." Unwilling to "stoop" by explaining his feelings toward her, the duke admits that he "gave commands; / Then all smiles stopped together." It seems, then, that he had her killed so that he could start over with another duchess. Just as his will overpowered hers during her life, the duke's will overpowers his auditor's during this rather one-sided conversation.