Continuity mistake: When Lois asks Chris who he's talking to on the phone, she get considerably closer to him between shots. (00:02:25)
Continuity mistake: After Lois accuses Stewie of peeing on the carpet, he asks her to bend down and slaps her with a glove. The glove remains in his hand in that cut, is still there when there is a wide shot of Peter, Stewie, Lois and Brian (you can just see it next to his trousers in his hand), but when it cuts back to Stewie and he starts on about "the outrages" etc, it is gone (the cut is instant, no time for him to put it back in his pocket). A common error, this one just struck me as strange, because the sandwich Stewie threw at Lois is there the entire scene. (00:03:35)
Continuity mistake: Just before Lois suggests they toilet train Stewie, she and Peter move considerably between shots. (00:03:55)
Continuity mistake: When Brian is at the psychiatrist's for the first time, the psychiatrist's chair changes position between shots. (00:08:20)
Continuity mistake: As Lois pats Brian, her elbow changes position. (00:16:45)
Continuity mistake: When Stewie has been picked up by Lois and is being kissed by her, Brian freaks out. When you first see Stewie and Lois, Stewie's hands are on her shirt, next shot, they're on her arms. (00:19:40)
