In "My Last Duchess," by Robert Browning, I think it is safe to say that the Duke is amoral with regard to his own behavior. He crassly draws aside the curtain revealing for his visitor his "last duchess" and then continues to explain to his guest her suspected infidelity. The very things that probably attracted him to her--her rosy complexion, her smile, and etc. are replicated by the artist, but the Duke suspects some untoward behavior on the duchess’s part. He is acquisitive by nature as we learn both from his marriage to the beautiful duchess and the bronze statue of Neptune. The fact that he can casually dismiss the last duchess "then the smiles stopped" indicates that he has no compunction about divesting himself of those assets he no longer considers valuable before moving on to his next acquisition this case his "next Duchess" who happens to be waiting downstairs.
the following e-note link might be useful