Rose is evil (Situational Irony)
Throughout the film, Rose is presented as a sometimes-naive, but ultimately supportive girlfriend to Chris. She wants to hear his concerns about meeting her white family for the first time, stands up for him when the policeman asks to see Chris' identification for no reason, and even agrees to leave her family when Chris is uncomfortable with all the unusual events that have been happening at the Armitage's house. Thus, it is particularly horrifying when, in an ironic twist, she is revealed to be the most villainous character in the film, having manipulated Chris the whole time. There is a specific irony in seeing such a calm and self-assured white ally transform suddenly into a cold-hearted white supremacist.
Detective Latoya doesn't believe Rod (Dramatic Irony)
When he suspects that Chris is in danger, Rod goes to visit Detective Latoya and delivers a long monologue to her and her coworkers about his suspicions that Chris has been kidnapped and turned into some kind of sex slave. The viewer, having seen what is happening to Chris, knows that Rod is onto something, even if his humorous monologue seems a little far-fetched. At the end of Rod's impassioned monologue, Latoya and the other detectives begin laughing. She has clearly brought them in because she thinks Rod's story is so absurd. The disquieting and humorous dramatic irony is that Rod is basically right, but they do not take him seriously.
Rose's earphones (Dramatic Irony)
In order to escape the Armitage house, Chris has to kill each Armitage family member one at a time. It is a horrible bloodbath, violent and loud, but Rose cannot hear it. Upstairs in her room, she is sitting on her bed listening to "I Had the Time of My Life" on her earphones and so is completely unaware of the ruckus downstairs. This instance of dramatic irony—in which we know about Chris' escape before she does—is something of a relief, as the viewer is on Chris' side.
Rod is in the cop car (Situational Irony)
At the end of the film, a cop car pulls up just as Chris is strangling Rose in the middle of the road. While the viewer knows that Chris is acting to defend his life, the presence of the police does not bode well for Chris' fate, and the image of him strangling a pretty white girl doesn't look good. For a moment, the viewer is meant to worry that Chris will be wrongfully arrested or brutalized by the police. Thankfully, however, the driver of the car is Rod, Chris' best friend, and Chris can make his escape without fear.
