Leaving a six month old baby in the house alone
After Cynthia tells the Conti's that babies are not welcome in the dinner party organized by her for her husband Graham, Anne, and her husband make the decision of leaving the baby alone in the house to attend the party next door. This decision is quite ironic given the fact that Anne knew that it was irresponsible of her to leave the baby all alone in the house after the sitter canceled. In fact, she is quite aware of the reaction other mother's would have when they came to know that she had left a six-month-old infant alone:
"She wonders what the other mothers in her moms in her group would think if she ever told them. We left our six-month-old baby home alone and went to a party next door. She imagines all their jaws dropping in shock, the uncomfortable silence..." (The Couple Next Door, 10).
Anne's decision to leave the baby alone brings to light her irresponsibility as a mother.
Cynthia flirting with Marco
At the birthday party that Cynthia organized for her husband Graham, Cynthia flirts publicly with Marco, Anne's husband despite she herself being married to Graham. Moreover, she does this in the presence of Anne. It is also ironic that Annes thinks of Cynthia and Marco as a "striking couple." Instead of Anne stopping them, she blames it on the paranoia associated with the alcohol she had consumed earlier.
Anne's lack of awareness on the clothes her daughter was wearing
When detective Rasbach asks Anne what clothes her daughter was wearing the night of the kidnap, it becomes evident that she does not know. Also, she says that she changed the baby in the dark, and had a little bit to drink. This is despite her being a nursing mother. Anne's behavior is cynical, contemptuous and derisive. Her behavior as a mother is largely ironic as it is generally expected that mothers should be epitomes of good and upright moral decisions. She says:
"I don't know. I'd had a bit to drink. I was tired. It was dark. I nurse her in the dark for her last feeding, so she won't wake up completely. She spit up on her onesie, and when I changed her diaper, I changed her outfit, too, in the dark. I threw the pink one in the laundry-- I thought I did--and I took another one out of the drawer. She has a lot of them. I don't know what color" (The Couple Next Door, 52).
Marco's decision to not turn on the lights when checking on the baby
It is ironic that Marco having gone to check on the baby does not switch on the lights in order for him to see the baby. The irrationality of Marco's decision becomes apparent since it is not clear how he might have been able to be sure that the baby was in the crib during his visit to check up on her: " I didn't turn the lights on when i checked on her" (The Couple Next Door, 52).
Anne's blame on Marco
While it is true that Marco convinced his wife Anne to leave the baby Cora alone in the house, it is ironic that Anne agrees to leave the baby behind and later blames her husband for it despite having been aware of the irresponsible nature of that decision. Even after Marco apologizes, Anne does not forgive him despite being aware of the fact that he was sorry. Her blame on Marco is completely unwarranted given that she had a choice as a mother and chose consciously to leave the baby behind for a party, an outcome of which was the baby's kidnapping.
