Not faithful; not observant of promises, vows, allegiance, or duty; violating trust or confidence; treacherous; perfidious; as, an unfaithful subject; an unfaithful agent or servant.
Unfaithful is a 2002 movie directed by Adrian Lyne. It was adapted by Alvin Sargent and William Broyles Jr. from the French language film La Femme infidèle by Claude Chabrol.
Unfaithful is a pop song written by Ne-Yo, Tor Erik Hermansen and Mikkel S. Eriksen for Rihanna's second album A Girl Like Me (2006). It was produced by Stargate and released as the album's second single in mid-2006.