[s4e22] Sibling Rivalry -

: Peter finds he is actually attracted to Lois’s new, much larger physique. The two rediscover their spark through what Peter calls "fat sex," and he actively encourages her to continue gaining weight.

: The bingeing eventually catches up with Lois, leading to a heart attack. She is rushed to the hospital for emergency liposuction, which returns her to her original size and ends their "weight-gain" phase. The Subplot: Stewie and Bertram [S4E22] Sibling Rivalry

The story of follows two chaotic plotlines: one involving Peter and Lois’s marriage and another centered on Stewie’s battle for preschool dominance. The Main Story: Peter and Lois : Peter finds he is actually attracted to

: Stewie encounters his half-brother, Bertram (born from a sperm bank donation Peter made years earlier), at the playground. The two share the same genius-level intellect and megalomaniacal ambitions. She is rushed to the hospital for emergency

: One famous gag features the letter "Y" being mocked by other vowels for only being a "semi-vowel". Family Guy S4E22: "Sibling Rivalry" Recap - TV Tropes