Liar Liar is an episode of the ALVINNN!!! and The Chipmunks series.
On the way to buy a cool pair of basketball shoes, Dave and Alvin pull over to help a father and son with a flat tire. Alvin doesn't want to stop, but Dave states it's the right thing to do and makes Alvin talk with the man's son during the wait. Finished, Dave discovers Alvin told a lie that he has an older son who races cars in the jungles of China. Dave supports the lie after Alvin insists. The next day at school, Miss Smith expresses her interest in meeting their brother and holds a school assembly to introduce Kent Harris, the stranger Dave helped who also happens to be a creator of documentaries. On announcement of his next piece, The Chipmunks lie to their friends and quickly leave the school before Miss Smith could talk with Dave. Dave is told the new information though the boys convince him to continue the lie. Smith and Harris stop by to talk though Alvin makes matters worse after claiming a film has already been made on his older brother. Seeing as no such film exists, Dave and the boys begin filming one in their living room. Post-editing, Simon claims the film's ridiculous and they should "end it," but Alvin mistakenly hears "send it." Smith, Harris, and the principal see it and call Dave to speak with him. He gets an earful from them on his poor decision making. On the way home, Dave stops to help a lady with a flat tie, but the boys spill the lies and she quickly drives off with the flat tire.
- "Everybody Lies" 
- Goof: Janice Karman was credited for directing the episode twice: before and after the titlecard.
- When this episode premiered in the US, it aired with a rerun of Double Trouble.