Continuity mistake: The bag of crisps that is on Peter's lap at the start have completely disappeared when Lois walks in a few seconds later. (00:01:50)
Other mistake: When Lois is saying about not having a spark in their marriage any more, the headboard of the bed keeps changing shades from light to dark in very quick succession. (00:03:00)
Continuity mistake: When Peter crashes the car, Lois' seatbelt keeps disappearing and reappearing from the car. (00:05:02)
Continuity mistake: When Brian tells Meg and Chris to sit on the sofa, Meg's hands change position from between her legs to on her knees between shots. (00:07:10)
Continuity mistake: When Chris hides the vodka from his teacher, he holds his right hand behind his back with his left arm at his side, but in the next shot, both his hands are behind his back. (00:09:40)
Answer: Lacey Chabert was the actress who originally voiced Meg in early episodes. She left of her own accord due to being in school and other acting work; Seth MacFarlane has stated there was no tension with her leaving, but it makes for a handy joke for the show.
Jon Sandys ★