Kate Hudson and Alex Rodriguez? Macauley Culkin and Mila Kunis? Niley? Some celebrity relationships come and go so quickly, it can be hard to keep track. Some are so brief, we can forget about them altogether. No worries -- we're here to remind you of all your favorite lost loves.
Gregg Allman and Cher
Cher and Gregg Allman met, married, divorced, remarried, made an album together ("Two the Hard Way") and had a son, Elijah Blue Allman, all within the span of four years from 1975 to 1979.
Ciara and Bow Wow
Ciara and Bow Wow were one of the hottest couples of 2005, but parted ways just one year later. In a 2016 interview with VladTV, Bow Wow explained the reason for the break up saying, "I started being in the streets a lot, clubbing, not wanting to go home. You know how that go. I just got sucked into the game. We just went our separate ways."
Tupac Shakur and Madonna
Madonna, 58, revealed on Howard Stern's SiriusXM radio show in March 2015 that she had dated Shakur, who was killed in a 1996 shooting at age 25. Recalling her infamous 1994 appearance on CBS' "Late Show with David Letterman," she told Stern she had cursed on the late-night talk show because, "I was in a weird mood that day. I was dating Tupac Shakur at the time and the thing is he got me all riled up on life in general. So when I went on the show I was feeling very gangsta."
Emily Blunt and Michael Bublé
Before she married John Krasinski, Emily Blunt dated Michael Bublé for three years until they eventually called it quits in 2008.
Britney Spears and Colin Farrell
Britney Spears accompanied Colin Farrell to the premiere of his film "The Recruit." Despite appearing together for a short time in 2003, they claimed they were just friends.
Ryan Gosling and Sandra Bullock
In 2002, despite a 16-year age difference, Ryan Gosling and Sandra Bullock fell in love on the set of their film "Murder By Numbers." However, the couple split the following year.
Ashanti and Nelly
Singer-actress Ashanti and rapper Nelly dated for 10 years beginning in 2004. "I think sometimes when people have their own insecurities it allows them to act out of character. I've been betrayed," Glen Cove native Ashanti said in 2015 during an appearance on the Meredith Vieria Show one year after the couple split.
Katy Perry and Travie McCoy
Katy Perry and "Billionaire" singer Travie McCoy dated for two years, until December 2008. The pair originally met in 2006 on the set of Gym Class Hero's music video for "Cupid's Chokehold," Perry played McCoy's love interest.
Cameron Diaz and Matt Dillon
Cameron Diaz and Matt Dillon started dating in 1995 and split shortly after filming "There's Something About Mary" in 1998.
Kate Moss and Johnny Depp
Johnny Depp began dating supermodel Kate Moss in 1994 before splitting four years later. Moss later told Vanity Fair that their breakup was hard, saying, "There's nobody that's ever really been able to take care of me. Johnny did for a bit."
Orlando Bloom and Kate Bosworth
Orlando Bloom and Kate Bosworth dated on-and-off from 2003 to 2006. Bloom went on to marry model Miranda Kerr, while Bosworth married director Michael Polish.
Taylor Swift and Harry Styles
Taylor Swift and Harry Styles reportedly dated for a brief time in late 2012. Swift's songs, "Out of the Woods" and "Style," were rumored to be about him. In a recent interview with Rolling Stone, Styles said he did not know if they were about him or not.
Macaulay Culkin and Mila Kunis
Before she married Aston Kutcher, Mila Kunis dated Macaulay Culkin from 2002 to 2011. "He was huge," she said on "The Howard Stern Show. "You couldn't walk down the street with him. He always had this weird attraction, like fans just screamed when they saw him!"
Wilmer Valderrama and Lindsay Lohan
Wilmer Valderrama allegedly began dating Lindsay Lohan when she was 17 and he was 24 but the couple didn't go public until after she turned 18. They made headlines everywhere in 2004 when they broke it off after a year of dating.
Nicolas Cage and Patricia Arquette
Nicolas Cage and "Medium" actress Patricia Arquette married in 1995 and divorced in 2001.
Gwyneth Paltrow and Brad Pitt
Brad Pitt and Gwyneth Paltrow began dating in 1994 after meeting on the set of "Seven." He popped the question two years later, but they never made it down the aisle as they called off their engagement in 1997.
Nick Cannon and Kim Kardashian
"America's Got Talent" host Nick Cannon dated Kim Kardashian from September 2006 to January 2007. He went on to tell Howard Stern that he broke it off after she lied to him about her infamous sex tape.
Michelle Rodriguez and Cara Delevingne
Before Cara Delevingne went public with her bisexuality, she briefly dated "Fast and Furious" star Michelle Rodriguez. The couple split in 2014.
Jamie Dornan and Keira Knightley
Kiera Knightley met "50 Shades" star Jamie Dornan in August 2003 -- before he became an actor. The pair dated for two years before splitting in August 2005.
Naomi Watts and Heath Ledger
Naomi Watts and the late Heath Ledger began dating in 2002, when they worked together on the Australian film "Ned Kelly." People magazine reported the couple dated for 16 months until their split in 2003.
Alexis Bledel and Milo Ventimiglia
Milo Ventimiglia joined "Gilmore Girls" in 2001, playing Alexis Bledel's on-screen boyfriend, Jess. The two began dating in real life but split in 2003.
Paris Hilton and Benji Madden
In the early 2000s, Nicole Richie was dating Good Charlotte singer Joel Madden, so it makes sense that her then-best friend, Paris Hilton, would date Madden's twin brother and bandmate, Benji Madden. The two went public with their relationship in 2007 but called it quits by 2008.
Lenny Kravitz and Nicole Kidman
Nicole Kidman recently told Net-a-Porter that in 2003 she had been engaged to Lenny Kravitz. She confirmed it when asked about "Big Little Lies" co-star Zoë Kravitz saying, "Well, I knew Zoë because I was engaged to her father. It's all in the family!" There's no bad blood between the two and she went on to say, "I love Lenny; he's a great guy."
Wilmer Valderrama and Mandy Moore
Wilmer Valderrama and Mandy Moore dated from 2000 to 2002. The two apparently hold no grudges and shared a series of selfies when they bumped into each other while filming shows for NBC in 2016.
Sheryl Crow and Owen Wilson
Sheryl Crow met actor Owen Wilson during her foray into acting on the film "The Minus Man." She dedicated her song "Safe and Sound" to Wilson before they broke up in 2001.
Cameron Diaz and Justin Timberlake
Actress Cameron Diaz and singer Justin Timberlake met at the Kids Choice Awards in 2003. They began dating and she even toured with him before eventually splitting in 2007.
Ashton Kutcher and Brittany Murphy
The late Brittany Murphy and Aston Kutcher met in 2003 while filming "Just Married." Rumors of their engagement circulated, but were never confirmed. The relationship fizzled after just a few months, and Kutcher went on to marry Demi Moore, and Murphy married Simon Monjack.
Channing Tatum and Amanda Bynes
Amanda Bynes and Channing Tatum met on the set of "She's The Man," and dated briefly. But when Tatum met Jenna Dewan, he left Bynes for his future wife.
Salma Hayek and Edward Norton
According to the New York Daily News, Salma Hayek and Edward Norton began dating after being set up by their chiropractor in 1999. The couple hit it off at first but called it quits by 2003.
Hilary Duff and Joel Madden
Hilary Duff and rocker Joel Madden got together when Duff was only 16 and Madden was 24. They coupled right after Duff left "Lizzie McGuire" in 2004 and stayed together until 2006.
Minka Kelly and Donald Faison
"Friday Night Lights" actress Minka Kelly and "Scrubs" actor Donald Faison dated from 2004 to 2005 before she coupled up with John Mayer and later, Derek Jeter.
Madonna and Sean Penn
Actor Sean Penn and Madonna met and married in 1985. Madonna filed for divorce in 1987 but the two stayed together until she filed again in 1989. Penn was allegedly abusive towards Madonna, but she stated in 2015 court documents that the allegations were "completely outrageous, malicious, reckless, and false."
Whitney Houston and Ray J
In the last year of her life, Whitney Houston had a public relationship with "Love & Hip Hop: Hollywood" star Ray J. During his time on the UK's "Celebrity Big Brother," he opened up to singer Stacy Francis saying that he blamed himself for factors leading to Houston's death in 2012.
Brooke Shields and Andre Agassi
Brooke Shields and tennis star Andre Agassi were married in1997, but divorced two years later. In 2009, Agassi told the Today show, "I think at that time in my life I couldn't be married to anyone."
Jack Nicholson and Lara Flynn Boyle
Jack Nicholson and Lara Flynn Boyle had an on-again-off-again relationship from 1999 through 2006. Boyle, who had been dating actor David Spade, told Vanity Fair that Nicholson asked her out in front of him.
Jennifer Garner and Michael Vartan
Before she married Ben Affleck, Jennifer Garner dated "Alias" co-star Michael Vartan. Their relationship lasted from mid-2003 through August 2004.
Zac Efron and Vanessa Hudgens
After meeting on the set of "High School Musical," Zac Efron and Vanessa Hudgens dated from 2006 to 2010.
John Mayer and Jennifer Aniston
Jennifer Aniston, who is now married to Justin Theroux, and singer John Mayer dated from 2008 to 2009.
Nicky Hilton and Kevin Connolly
Heiress Nicky Hilton dated "Entourage" star Kevin Connolly on-and-off before her marriage to Todd Meister in 2004. After her divorce only a few months later, the pair got reunited before ultimately parting ways in 2006.
Demi Moore and Emilio Estevez
Demi Moore and Emilio Estevez dated for two years before becoming engaged in 1985. They split in 1987 without tying the knot, but reportedly remain good friends.
Kirsten Dunst and Jake Gyllenhaal
From 2002 to 2004, Kirsten Dunst and Jake Gyllenhaal were one of the hottest couples in Hollywood. Nobody knew why they broke up but Dunst later admitted that they both knew from the beginning it would never last.
Michelle Trachtenberg and Pete Wentz
"Gossip Girl" actress Michelle Trachtenberg dated Fall Out Boy bassist Pete Wentz in 2006 before his marriage to Ashlee Simpson. The two were spotted together after his divorce from Simpson in 2011, but they never rekindled their early 2000s romance.
Jessica Biel and Chris Evans
Jessica Biel and Chris Evans met on the set of "Cellular" in 2004 and dated until 2006. Biel went on to marry Justin Timberlake.
Matthew Morrison and Kristen Bell
Kristen Bell and "Glee" actor Matthew Morrison dated for a short time while in college.
Penelope Cruz and Tom Cruise
Tom Cruise and Penelope Cruz met in 2000 while filming "Vanilla Sky" and began dating in 2001, right after his 10-year marriage to Nicole Kidman ended. The pair dated until 2003.
January Jones and Josh Groban
Singer Josh Groban reportedly said his three-year relationship with January Jones was the longest relationship he'd ever had. The two dated from 2003 to 2006, right before Jones landed a role on the hit series, "Mad Men."
Kate Hudson and Alex Rodriguez
"How to Lose a Guy in 10 Days" actress Kate Hudson dated former Yankees player Alex Rodriguez briefly in 2009. The two reportedly broke up because Hudson thought A-Rod wasn't over ex-girlfriend, Madonna.
Jennifer Esposito and Bradley Cooper
"Blue Bloods" actress Jennifer Esposito and actor Bradley Cooper dated in the early 2000s. They even briefly married from December 2006 until May 2007.
Miley Cyrus and Nick Jonas
Miley Cyrus and Nick Jonas, far left, known together as "Niley," dated as teens from 2006 to 2008.
Katie Holmes and Chris Klein
Before she married Tom Cruise, Katie Holmes dated "American Pie" actor Chris Klein. The two were engaged in 2003 but split in 2005.
Ryan Reynolds and Alanis Morissette
"Deadpool" actor Ryan Reynolds, who is married to Blake Lively, was engaged to "Ironic" singer Alanis Morissette. The couple dated from 2002 to 2007 before parting ways.
Brody Jenner and Avril Lavigne
The former "Hills" star and Kardashian step-sibling dated the punk rocker for two years before eventually splitting in 2012. Lavigne went on to marry Nickleback frontman, Chad Kroeger, while Jenner is currently engaged to Kaitlynn Carter.
Hilary Duff and Aaron Carter
Singers Hilary Duff and Aaron Carter dated as teens in the early 2000s before a love triangle with Lindsay Lohan tore them apart. After Duff's divorce from Mike Comrie, Carter tweeted what appeared to be declarations of his love for his old flame.
Michael Jackson and Lisa Marie Presley
"The King of Pop" and the daughter of the "King of Rock and Roll" married in 1994. In 1996, they filed for divorce but Presley later admitted they spent 4 years after their divorce dating on-and-off again.