When Claudia starts behaving erratically for no apparent reason, Jimmy and Henry tell Sean that their mom is losing it; she's gone crazy. Sean investigates and discovers that Claudia has been sneaking around and smoking even though they both quit ten years earlier. Sean's not going to cut her any slack, but she protests that her job is stressful beyond belief, and it's not as if Sean never does anything that's unhealthy. At least, says Sean, he now understands why Claudia's been avoiding him; he thought he'd done something to make her angry. He was so convinced that she was upset with him, that he even thought he knew the reason. Sean and Claudia were browsing at a thrift shop, when Claudia spotted an armoire that she liked. Sean made fun of it, but later thought that this is what has been making Claudia act so standoffish. Lily arrives and dramatically announces that she's just had the most embarrassing night of her life. She made an ass of herself, and Dean thinks she's an idiot. Eddie tells Sean to ease up on Claudia; he remembers how hard it is to quit smoking. Walt tells Eddie he thinks Claudia is talking about cigarettes. Henry says he doesn't want his mom to smoke, because she'll die and then he'll have to put on a suit and go to church. Sean presents Claudia with the armoire that he went back and bought in an attempt to appease her. Claudia thinks he's nuts. Sean hears Lily's cell phone ringing, and Claudia is forced to confess that she bought it for Lily as a bribe, so Lily wouldn't bust her. Lily reveals that her new phone is the source of her humiliation. She accidentally hit the re-dial button while the phone was in her pocket and recorded a conversation with Claudia on her friend's voice mail. Now all her friends, including Dean, have heard Lily say that Dean is like oxygen for her; she needs him to breathe. Later Dean shows up at the Finnerty house, and Lily's mortified, but her mood quickly changes when he suggests that they get together the next day. She's not even unhappy when Claudia cancels her cell phone, because now, she says, she has a boyfriend. And Claudia hits rock bottom when she scales their back fence and lurks around in the O'Keefe's backyard in an attempt to avoid being caught smoking again by Sean.