Irony in "Porphyria's Lover"

Robert Browning's poem entitled "Porphyria's Lover" utilizes both dramatic and situational irony. The irony makes the poem unpredictable and exciting, yet horrifying and disturbing. It also reveals much about the mental state of the speaker.
According to our textbook, dramatic irony "occurs when a speaker believes one thing and readers realize something else"(Kirszner & Mandell, 719). In this poem, dramatic irony is used when the speaker states, "I am quite sure she felt no pain" (line 42). Although he seems to adamantly believe his statement, the reader knows that as the victim of a strangling, Porphyria must have felt some pain. Another point at which dramatic irony occurs is when the speaker says that Porphyria now has her "utmost will" (line 53), as she is joined with him forever. However, the reader knows that Porphyria's will was to seduce her lover and gain his affection, not to lose her life.
Situational irony "occurs when the situation itself contradicts readers' expectations" (Kirszner & Mandell, 721). Of course, the most obvious example of situational irony in "Porphyria's Lover" is the fact that this evening tryst ends in murder, instead of the expected seduction. Another example of situational irony occurs after the murder of Porphyria. One would think that her lover would jump back in horror over what he had done, or try to hide his sin, yet he just sits there with her, as though she were still alive (lines 58-59).
Thus, both the dramatic and situational ironies help to reveal the mental instability of the speaker, as he acts much differently than a sane person would under his circumstances.