Rich Man, Poor Man (1976)

S13E12 Stewie Is Enceinte

Feeling fed up with their friendship, Brian tells Stewie he no longer wants to spend time together. In a desperate bid to mend their bond, Stewie hatches a plan to create a baby—well, several babies—using Brian's DNA to inseminate himself. Simultaneously, Peter, Joe, Quagmire, and Cleveland join forces in an effort to produce a viral video that will capture everyone's attention.