Which Family Guy episode consists of teaching the kids about dating and purring like a walrus?

Answer 1

That would be "Stewie Griffin: The Untold Story", which originally was a straight to DVD feature. However, FOX aired it and split it into three half-hour episodes: "Stewie B Goode", "Bango Was His Name-o", and "Stu and Stewie's Excellent Adventure". I believe the quote you're looking for was in the second part.