Alan Matthews 46th birthday is coming up in three days and Eric is trying to plan a surprise party for him. Meanwhile, Shawn gets a letter from his deadbeat mother that has him searching into his family tree and relapsing into his alcoholism.
Tropes:
- Missing Mom: It's not explained why Shawn's newly discovered biological mother wasn't around when Shawn was growing up.
- Off the Wagon: The first and last time Shawn drank in the series was 2 seasons ago in "If You Can't Be With the One You Love." Realizing he is The Alcoholic and needs to stay away from it, he hasn't drank since. And then his mother tells him she's not his birth mother and the birth mother he tries to look for cannot be found. Shawn shows up a drunken and belligerent mess to Alan's 46th birthday party, ruining it.
- Quit Your Whining: As he starts spiraling about his severe Parental Abandonment issues at Alan's party, Shawn stops himself from speaking to put his head in his hands and frustratedly tell himself, "Stop your whining."
- Talking to the Dead: A drunk Shawn goes to the cemetary and begins ranting at Chet's grave demanding to know how he could die without ever telling him about his mothers and what to do about the Matthews' offer to adopt him. This then quickly morphs into a Dead Person Conversation, as Chet appears. Once Shawn resolves his issues, Chet walks out of frame and Cory appears, who then proceeds to play the trope straight again by talking to Chet's grave, as well.
- You're Not My Father: When Alan tries to talk to Shawn as he begins to have a meltdown at his party, Shawn brushes him off telling him "you're not my dad" before launching into a painful shpiel about how he's lived a life of abandonment, with 2 mothers who don't seem to want him and an absentee father who only showed up later in life, right before dying.
