Family Guy S12 E17 The Most Interesting Man in the World

"Don't die laughing. We could get sued."

When Peter takes Stewie to the park for some quality father-son time, he mistakenly takes the wrong baby home, prompting Lois to call him an idiot. Determined to prove to her that he's a responsible adult, Peter goes on a business trip to Chicago and returns as an intelligent, classy person.