When Brian catches Stewie "cheating" on Rupert, Stewie asks Brian to not tell him. Stewie mentions that Rupert might kill himself if he knew, as Rupert had "been through so much already, in that he watched his own brother drown". This is a reference to the plot of the film "Ordinary People".
At the end, after Quagmire is untied from bondage, his father asks if he's alright. He replies "No, I'm pretty fucking far from alright", mimicking the scene in the basement of the pawn shop where Butch asks Marcellus Wallace how he is after one of their captors ties him up and rapes him.