Hollywood love triangles

What went down: It turns out actor Billy Crudup really is all about the drama. The thespian was expecting his first child with longtime girlfriend Mary-Louise Parker in 2003 when he dumped her after seven years together. It seemed Crudup, who met Parker during a 1996 revival of William Inge’s play “Bus Stop,” had fallen for another actress. In 2004 he confirmed he was dating his “Stage Beauty” costar Claire Danes, although the couple denied an affair. The relationship eventually dissolved in 2006.  (From left: Showtime; Getty Images; Andrew H. Walker / Getty Images)

What went down: Britney Spears started looking more like a home wrecker than a pop princess in 2004 when she fell for backup dancer Kevin Federline. The scandal broke when he walked out on his pregnant girlfriend, Shar Jackson, and their daughter Kori to be with the singer. The pair eventually filmed a reality show, got married and had two children of their own before a major split in 2007.

K-Fed manned up in 2010 and apologized to Jackson for his “selfish” ways, during an episode of VH1’s “Celebrity Fit Club.”  (Frazer Harrison / Getty Images)

What went down: Were Brad Pitt and Angelina Jolie playing house behind Jennifer Aniston‘s back? That’s the popular perception after Pitt and Jolie hit it off so well on the set of “Mr. and Mrs. Smith.” Though there were apparently problems between Pitt and Aniston before the movie started -- rumors about Pitt wanting a family and Aniston wanting to put it off -- nothing was ever really confirmed in terms of why the couple broke up. But it was very, even conveniently, soon after that Pitt and Jolie were adopting and having babies.  (Gary Friedman / Los Angeles Times)

What went down: “Underworld,” indeed. Playing a leather-bound vampire soldier, actress Kate Beckinsale went into the filming of the vampires vs. werewolves saga with longtime boyfriend, fellow Brit Michael Sheen (the David Frost of “Frost/Nixon”), as her costar. Maybe it was Len Wiseman’s excellent direction of the movie, but Beckinsale broke it off with Sheen, with whom she had a daughter, during the movie production and soon after began a relationship with Wiseman. The two married a year later. Beckinsale recently signed on to “Underworld 4.”  (Kevin Winter / Getty Images)

What went down: Woody Allen and Mia Farrow were together for 12 years until they split due to Allen’s desire to be with (romantically) her adopted daughter from a previous marriage, Soon Yi Previn. Scandal! Through court cases involving child-abuse charges and custody battles, Allen and Previn -- 35 years separating them -- remained together and wed six years after their relationship went public.  (Juan Naharro Gimenez / Getty Images)

What went down: If rock ‘n’ roll myths are to be believed, Pattie Boyd is responsible for many a hit tune. Most notably, perhaps, “Layla” by Eric Clapton. The song was cut in 1970 and released on Derek and the Dominos’ “Layla and Other Assorted Love Songs.” At the time, Clapton was believed to be infatuated with Boyd, whom Harrison had met while filming “A Hard Day’s Night” and later married. Boyd rebuffed Clapton’s advances, although the two were friends, and when her relationship with Harrison went south, Clapton and Boyd’s friendship became a romance. One problem: Clapton, according to many accounts from Boyd, was struggling with illegal substances at the time, and the artist’s refusal to seek help is one reason the relationship ultimately fell apart. However, while married to Boyd, Clapton had numerous affairs, even having a daughter with Yvonne Kelly while married to Boyd. The pair divorced in 1989.  (Charles Rex Arbogast / Associated Press)