Betrayal is a play written by Harold Pinter in 1978. Critically regarded as one of the English playwright's major dramatic works, it features his characteristically economical dialogue, characters' hidden emotions and veiled motivations, and their self-absorbed competitive one-upmanship, face-saving, dishonesty, and (self-)deceptions.

Inspired by Pinter's clandestine extramarital affair with BBC Television presenter Joan Bakewell, which occurred for seven years, from 1962 to 1969, the plot of Betrayal exposes different permutations of betrayal and kinds of betrayals occurring over a period of nine years, relating to a seven-year affair involving a married couple, Emma and Robert, and Robert's "close friend" Jerry, who is also married, to a woman named Judith. For five years Jerry and Emma carry on their affair without Robert's knowledge, both cuckolding Robert and betraying Judith, until Emma, without telling Jerry she has done so, admits her infidelity to Robert (in effect, betraying Jerry), although she continues their affair. In 1977, four years after exposing the affair (in 1973) and two years after their subsequent break up (in 1975), Emma meets with Jerry to tell him that her marriage to Robert is over. She then lies to Jerry in telling him that, "last night", she had to reveal the truth to Robert and that he now knows of the affair. The truth however, is that Robert has known about the affair for the past four years.

Betrayal (or backstabbing) is the breaking or violation of a presumptive contract, trust, or confidence that produces moral and psychological conflict within a relationship amongst individuals, between organizations or between individuals and organizations. Often betrayal is the act of supporting a rival group, or it is a complete break from previously decided upon or presumed norms by one party from the others. Someone who betrays others is commonly called a traitor or betrayer. Betrayal is also a commonly used literary element and is often associated with or used as a plot twist.

Roger L. Jackson, author of the article, The Sense and Sensibility of Betrayal: Discovering the Meaning of Treachery Through Jane Austen, writes that "there has been surprisingly this little written about what we even mean by the term". In psychology, practitioners describe betrayal as the breaking of a social contract; however, critics of this approach claim that the term social contract does not accurately reflect the conditions and motivations for, and effects of, betrayal. Philosophers Judith Shklar and Peter Johnson, authors of The Ambiguities of Betrayal and Frames of Deceit respectively, contend that while no clear definition of betrayal is available, betrayal is more effectively understood through literature.

Play may refer to:

Jeremy John Irons (born 19 September 1948) is an English actor. After receiving classical training at the Bristol Old Vic Theatre School, Irons began his acting career on stage in 1969, and has since appeared in many London theatre productions including The Winter's Tale, Macbeth, Much Ado About Nothing, The Taming of the Shrew, Godspell and Richard II. In 1984, he made his Broadway debut in Tom Stoppard's The Real Thing and received a Tony Award for Best Actor.

Irons's first major film role came in the 1981 romantic drama The French Lieutenant's Woman, for which he received a BAFTA nomination for Best Actor. After starring in such films as Moonlighting (1982), Betrayal (1983), and The Mission (1986), he gained critical acclaim for portraying twin gynaecologists in David Cronenberg's psychological thriller Dead Ringers (1988). In 1990, Irons played accused murderer Claus von Bulow in Reversal of Fortune, and took home multiple awards including an Academy Award for Best Actor. Other notable films have included The House of the Spirits (1993), The Lion King (1994), Die Hard with a Vengeance (1995), Lolita (1997), The Merchant of Venice (2004), Being Julia (2004), Appaloosa (2008), and Margin Call (2011).

Bullet for My Valentine are a Welsh heavy metal band from Bridgend, formed in 1998. The band is composed of Matthew Tuck (lead vocals, rhythm guitar), Michael Paget (lead guitar, backing vocals), Jason James (bass guitar, backing vocals), and Michael Thomas (drums). They were formed under the name Jeff Killed John and started their music career by covering songs by Metallica and Nirvana. Jeff Killed John recorded six songs which were not released; two of these tracks were reworked later in their career as Bullet for My Valentine. Financial difficulties dictated the name change, which was followed by a change in music direction. In 2002, the band secured a five-album deal with Sony BMG. The band has stated that their music is influenced by classic heavy metal acts such as Metallica, Iron Maiden, and Slayer. The band is part of the Cardiff music scene.

Bullet for My Valentine's debut album, The Poison, was released on 3 October 2005 in the United Kingdom and on 14 February 2006 in the United States to coincide with Valentine's Day hence their band name. The album entered the Billboard 200 in the US at number 128. It was certified Gold by the Recording Industry Association of America. The band made appearances at the Download Festival and Kerrang! XXV, and undertook a US tour with Rob Zombie. Bullet for My Valentine's second studio album, Scream Aim Fire, was released on 29 January 2008 and debuted at number four on the Billboard 200. The band's third album, Fever, was released on 26 April 2010 and debuted at number three on the Billboard 200. The band has sold over one million albums in the United States and nearly 2,500,000 albums worldwide and are the most-successful act in the Kerrang! Awards category of "Best British Band" with three wins.