An even older, but imo lesser-publicized Family Guy BE can be found in the episode where Quagmire almost marries a maid Peter won on a game show. Lois stops breastfeeding Stewie and her breasts get swollen. A short search yielded this sketchy clip (highlights at 12:10 and 14:00), though I'm sure there's some better quality video out there somewhere:
http://adventure.ma-play.com/f-anima...-Quagmire.html