Because we can't.
Everyone remembers Demi Moore with Bruce Willis, but did you know she dated Emilio Estevez before Bruce?
And before Matt Damon found love with a waitress, he dated several Hollywood starlets.
Click through to find out who Matt was linked to, as well as many other surprising hookups.
Melissa Joan Hart and Ryan Reynolds
The former teenage witch kisses and tells. Hart admitted to more than onscreen smooching the former "Sabrina the Teenage Witch" guest star.
He gave me this beautiful watch and ran out of my dressing room," she told Access Hollywood. "I chased him down and in the headlight of his car, I stopped him… and I just grabbed him and kissed him. We just made out all night… Ryan has grown up nicely."
Renee Zellweger and Kenny Chesney
Zelleweger and country singer Chesney met at a tsunami disaster relief event in January of 2005 and were married by May. The marriage only last four months before Zelleweger cited fraud as the reason for the annulment.
Edward Norton and Courtney Love
Back in the '90s, before Courtney Love was a train wreck, she dated her "The People Vs. Larry Flint" co-star, Ed Norton.
While the actor has chosen to lead a low-key life, Love has made headlines for drug abuse and legal battles. She publicly attacked Ed over financial matters via Twitter in 2010, calling him a "terrifically bad sexist."
He has since married Canadian film producer Shauna Robertson, who gave birth to their son in March 2013.
Jewel and Sean Penn
Sean has been spotted with a bevy of blond beauties, many while on breaks from his 16 year marriage to now ex-wife Robin Wright, including actress Scarlett Johansson and model Petra Nemcova.
But did you know he dated country/folk singer Jewel?
The odd couple reportedly got together in 1995, the same year 21-year-old Jewel released her debut album.
Straying far from the serious actor type, Jewel is now married to world champion rodeo cowboy Ty Murray.
Fergie and Justin Timberlake
Britney Spears is known as Justin Timberlake’s first love, but a 16-year-old JT dated then-23-year-old cougar Fergie in 1996 when she still went by Stacy Ferguson and was one third of girl band Wild Orchid. They were never spotted wearing matching head-to-toe denim outfits or anything, but it was the real deal for a hot second.
Since then, Justin dated a bevy of Hollywood beauties and finally settled down with Jessica Biel, and Fergie has a son with hunky husband Josh Duhamel.
Oprah Winfrey and Roger Ebert
It may have only been two dates in the ‘80s, but Oprah will never forget her fling with Roger. It wasn’t that the late film critic took her to a movie (shocking), but Oprah revealed on her 20th anniversary special in 2005 that it was over dinner at Hamburger Hamlet that Roger convinced her to syndicate her then-budding talk show by scribbling potential profits on a napkin.
And she never had to eat at a mediocre chain restaurant again.
Ebert was happily married to another accomplished beauty, Chaz Hammelsmith, until his death, and Winfrey is still with longtime love Stedman Graham.
Chelsea Handler and 50 Cent
Funny lady Chelsea Handler and rapper 50 Cent “casually dated” after she interviewed him on E! talk show “Chelsea Lately.” Handler told Howard Stern he pursued her with over-the-top flower deliveries (50 white roses) and flew to Nashville just to see her again.
They were together for a few months, she said, until he called her right before his ex, Ciara, was scheduled to appear on her show and told her that the singer still wanted him back. Chelsea admitted to harshly insulting him during that conversation, and that was the end of it.
Fiddy is now linked to model Tatted Up Holly, and Chelsea is on and off with hotelier Andre Balazs.
Jay Leno and Sharon Osbourne
Osbourne revealed on her show "The Talk" that she met Leno after seeing him perform in a comedy club soon after she moved to the U.S. in the 1970s, and the two had a brief fling. They both ended up meeting their respective current spouses - Leno's wife Mavis and Osbourne's husband The Prince of Darkness -- soon after, which she said ended up being "two of the longest marriages in Hollywood."
Jenny McCarthy and Donnie Wahlberg
Did you know the the new host of "The View" and the "Blue Bloods" star have been dating since the spring?
When Donnie appeared on "The Jenny McCarthy Show" in March, sparks were clearly flying.
"Let’s just say we visually give 50 Shades of Grey a run for its money," she says of the segment.. "It gets steamy. I mean like really steamy. Being turned on by a guy is always fun but to have it legitimately happen to you on TV is to be turned back into a 12-year-old. By the time we get into the groundbreaking interview, my face turns fifty shades of RED."
Sheryl Crow and Owen Wilson
The singer and the funny actor were pretty serious in the late '90s. She even dedicated a song on her 2002 album, C'mon C'mon to him called "Safe and Sound." According to the album's liner notes, the lyrics were inspired by their relationship.
Sandra Bullock and Matthew McConaughey
The pair dated for about a year when they shot "A Time to Kill" in 1996.
"We both have a lot of strong feelings for each other," Matthew has said. "It wasn't the right time before. I do love her, and will always love her. Absolutely."
Matthew is of course married to Camila Alves now, and raising three kids, while Sandra is raising adopted son Louis on her own.
Julia Roberts and Liam Neeson
Believe in or not, back in 1987, a 19-year-old Julia Roberts dated 35-year-old Liam Neeson while they were working together on the film "Satisfaction."
Calista Flockhart and Robert Downey Jr.
The co-stars who played sweethearts on Calista's hit show "Ally McBeal" in 2000 took their romance off-screen for awhile. But at the time, Robert was still battling drug addiction and faced two drug possession charges within six months. Needless to say, it was doomed to fail.
Now, Robert has been sober for years and married to Nancy Levin while Calista has been with Harrisson Ford since 2002.
Katie Couric and Bob Saget
Katie recently revealed to Howard Stern that she went on a "really fun" date with Bob Saget. But unfortunately it was just the one date, as he never called back. She also went out with "Survivor" host Jeff Probst and didn't hear back from him either.
“I can’t say that I was devastated that neither called me back,” she said. “I thought they were both nice guys … I don’t think there was real magic there with either, but I enjoyed spending time with them.”
Pink and Joey Fatone
Way back when Pink actually had Pink hair and Joey Fatone was making it big with 'N Sync, the young wannabe stars toured together and hit it off.
"Joey Fatone was in love with me," Pink reveals in the June issue of Glamour magazine. "He took me to Friendly’s on a date, and he bought me an ice cream. Such a sweetheart. He asked my dad’s permission."
Nick Lachey and Kim Kardashian
A few months after his very public breakup with Jessica Simpson in late 2005, Nick Lachey started seeing then no-name, Kim Kardashian. The romance only lasted a few months.
Nick moved on to his current fiance, Vanessa Minnillo, while Kim began seeing Ray J. – and we all know where that led…
For more pics of Kim or Nick, go to x17online.com.
Seal and Tyra Banks
Musicians sure do love their supermodels. Before Seal had three kids with Heidi Klum, he briefly dated her former Victoria’s Secret peer, Tyra Banks, in 1996.
Al Pacino and Diane Keaton
Many stars click on-and-off screen and that happened for Diane Keaton and Al Pacino when they filmed “The Godfather,” but it never got too serious since Al apparently wasn’t ready to settle down. "He's charming, hilarious, a nonstop talker,” Diane recalls. “There was an aspect of him that was like a lost orphan, like this kind of crazy idiot savant. And oh, gorgeous! I was mad for him. I worked hard on that one."
Tom Cruise and Cher
As Tom was trying to make a name for himself in the '80s, and Cher was already topping the Billboard charts, they briefly dated.
"It was a long, long time ago and neither one of us ever talked about it and I don't know why," Cher recently told ET. "I loved him though, he was amazing."
Michelle Williams and Jeremy Jackson
Before she was an Oscar winning actress or a star on "Dawson's Creek," Michelle had a fling with '90s actor Jeremy Jackson. The actor used to star on "Baywatch" and more recently appeared in "Celebrity Rehab."
"She was kind of like my first crush, puppy dog love," he told Howard Stern about Michelle, who was in an episode of "Baywatch" back in the day.
For more pics of your favorite stars, go to x17online.com.
Donald Faison and Minka Kelly
In 2005, long before Minka Kelly really made a name for herself in the entertainment world, Donald was a star on "Scrubs." The couple dated briefly, but he has gone on to shack up with Jessica Simpson's former assistant and she was on and off with Derek Jeter in 2011.
Donal Logue and Sofia Vergara
Before revamping her career with "Modern Family," Sofia dated her then co-star Donal Logue from "The Knights of Prosperity" in 2006.
Drew Barrymore and Christian Bale
It may be a stretch to say these two "dated," but they did go on a date, according to Christian.
Long before Drew Barrymore married her baby daddy Will Koppelman, she let Christian Bale take her out on a date.
"We went to see some bloody awful horror film, and that was the end of it," he recalls to Australian GQ. "She never called again."
Wait, he couldn't call her?
Kathy Griffin and Jack Black
Apparently these two made each other laugh at some point because Kathy Griffin recalls a night she spent with Jack in her latest book, Official Book Club Selection.
“One time, I spent the night at Jack’s place. I got up the next morning to take a shower so I could leave," she recalls. "When I got out, I couldn’t find anything to dry myself with. ‘Jack, where are the towels?’ I yelled out. He said, ‘Um, I just have one that I use for a bathmat and a towel. So it’s the one on the floor.’"
Wonder why this one didn't work out...
Shanna Moakler and Dennis Quaid
After splitting from fiance Oscar de la Hoya and before marrying Travis Barker, former Miss USA Shanna Moakler dated Dennis Quaid in 2001 for eight months. He even reportedly helped her decide to pose nude for Playboy. How sweet!
Heather Graham and James Woods
Back in 1992, when Heather was a bright-eyed 22-year-old and Woods was a 44-year-old established star, these two hooked up on the set of "Diggstown." The age-difference reportedly raised a few eyebrows, but that was before his latest relationship with Ashley Madison, who is 39 years his junior.
Kristen Johnson and Ryan Reynolds
Before Ryan Reynolds was an A-list star, he hooked up with "3rd Rock From the Sun" actress Kristen Johnson back in 1999. After the split, he began dating Alanis Morissette before splitting with her for Scarlett Johansson before splitting with her for Blake Lively. Whew!
Brooke Shields and Nicolas Cage
Back in the 1980s, America's sweetheart Shields dated Cage. The two even went public with their relationship at the 1987 premiere of his film "Moonstruck." The relationship fizzled out after a year.
LeAnn Rimes and Andrew Keegan
Back in the late 90s and before her scandalous affair with her now-husband Eddie Cibrian, LeAnn Rimes dated former teen hunk Andrew Keegan.
Things got serious between the pair and they were reportedly engaged to be married. But the actor allegedly had a fling with actress Piper Perabo, and the baby-faced couple split.
Vanessa Hudgens and Josh Hutcherson
The "Journey 2 the Center of the Earth" co-stars reportedly hooked up while filming together. But Hutcherson, who is celebrating big box office success with the "Hunger Games," recently said that while Hudgens broke his heart, they're still friends.
Halle Berry and Danny Wood
One of the hottest women in Hollywood dated the guy that nobody remembers from New Kids on the Block.
Back in 1989, the pair had a brief fling before his band mates reportedly pressured him to break it off claiming she was a groupie.
Bad move Danny. Bad move.
Brad Pitt and Christina Applegate
The "Married with Children" star walked out on Brad Pitt at the 1989 MTV Movie Awards.
"We were really good friends when I was about 16. We went to the awards and I ditched him! I left him there and I feel really bad about it...I really really do," she says. "I left with somebody else."
Lisa Kudrow and Conan O'Brien
It's common knowledge that the two funny stars are close friends, but they actually tried to be something more early on.
The former "Friends" star revealed to More magazine, “He was really smart, really funny and he thought I was funny. But we found we were better as friends."
Ashton Kutcher and January Jones
When model turned actress January Jones first moved to Los Angeles she dated “Punk’d” star Ashton Kutcher. But if it was up to him, she wouldn’t be starring on “Mad Men” today.
"[He] was not supportive of my acting," Jones, 32, told GQ in 2009. "He was like, I don't think you're going to be good at this.”
Now Ashton’s career is the one that’s not so hot while January stars in the hugely popular drama on AMC. “So – f**k you!” she quips. “He only has nice things to say now – if anything, I should thank him. Because the minute you tell me I can't do something, that's when I'm most motivated."
Kristen Bell and Matthew Morrison
The voice of “Gossip Girl” recently revealed that she dated the “Glee” star when they were both attending NYU. “I actually went to college with Matty Morrison,” Kristen told US Weekly at the premiere of “You Again.”
“We actually dated very briefly, so I’ll have to say maybe Matt Morrison is my favorite part of 'Glee' for various reasons.”
Wonder how fiancé Dax Shepard feels about that.
Demi Moore and Emilio Estevez
Demi Moore once dated guys her age.
In 1985 she was briefly engaged to her "St. Elmo's Fire" co-star Emilio Estevez who is a year older than she is.
Tom Green and Drew Barrymore
This courtship was bizarre to begin with, but they actually seemed to love each other...
Their high profile relationship finally came to an end in 2001 and it was surprisingly amicable.
"Drew is a wonderful woman, I love her very much. I wish our marriage could have worked out, I wish her much happiness," the comedian said about their six month matrimony.
Ted Danson and Whoopi Goldberg
According to people on set, the chemistry between these two wasn't only onscreen for "Made in America" in 1989.
"I'd walk in Whoopi's shadow for the rest of my life—I adore the woman," Danson said at the time.
Neither of them ever commented on the rumors, but their director practically confirmed them. "I was stunned at how easy and pleasant it was to work with them. There was an extreme affection and respect between them. It wasn't syrupy lovey-dovey stuff, just genuine."
David Gallagher and Megan Fox
Before Megan Fox was the sex symbol she’s considered today, she dated “7th Heaven” star David Gallagher upon arriving in Los Angeles.
Brian Austin Green is definitely a step up!
Tom Cruise and Sofia Vergara
Fans may have been a bit shocked when Tom Cruise shacked up with Katie Holmes in 2005, but just a few months before Katie, Tom was seen out and about with Columbian hottie Sofia Vergara.
Before Tom, the “Modern Family” actress dated Enrique Iglesias.
Adam Duritz and Courteney Cox
This romance proves that rockers really do get girls that are out of their league.
The Counting Crows singer has also dated Courteney's friend Jen Aniston.
He must be really nice.
Ryan Gosling and Sandra Bullock
Sandra Bullock, 47, had a May-December romance with Ryan Gosling, 30, in 2001.
Her good friend Hugh Grant would poke fun of the age difference by referring to her much younger boyfriend as "the child."
Winona Ryder and Matt Damon
Matt Damon and Winona Ryder were once Hollywood's "it couple" but they've both gone very different ways since they parted.
Winona has been in and out of trouble with the law, while Matt is settled down with three kids and making hit Blockbuster movies.
Kiefer Sutherland and Julia Roberts
He's known to be a Hollywood bad boy while she nabs the term, Hollywood Sweetheart.
But these two seemingly polar opposites almost wed in 1991.
Julia apparently had cold feet and called the whole thing off.
Sarah Jessica Parker and Robert Downey Jr
Before she became Carrie Bradshaw and he became “Iron Man,” these two were young and in love in the mid-‘80s - just before he hit rock bottom. "I liked to drink, and I had a drug problem, and that didn't jibe with Sarah Jessica, because it is the furthest thing from what she is,” Rob has admitted. “I was in love with Sarah Jessica… love clearly was not enough. I was meant to move on. And, after some heartache, she was meant to find her home with a great star."
After their seven year romance ended SJP married Matthew Broderick and her ex strongly approves. "He is a lot more gifted and grounded than I ever was,” he says.
Charlie Sheen and Kelly Preston
The former “Two and a Half Men” star was engaged to Kelly Preston in 1990, but their courtship ended soon after he accidentally shot her in the leg.
Meg Ryan and Russell Crowe
Meg Ryan briefly dated Russell Crowe while she was still technically married to Dennis Quaid. But she said that he "was not a home wrecker."
"He didn't talk and I'll always be grateful to him for that. But I did not leave my marriage for him," she explained on "Oprah." "I left because it was not working."
"Russell was incredibly gracious to me during a really hard time and in the aftermath," she said. "I empowered myself by not staying in the thing with Russell. I felt it was going to be repeating some similar patterns that I'd just gotten out of and it was a drag because I was crazy about him."
Juliette Lewis and Brad Pitt
Before breaking Jen Aniston's heart and adopting kids from around the world with Angelina Jolie, Brad Pitt was an up and coming actor dating Juliette Lewis.
They went out for four years.
Sean Penn and Madonna
So much has happened since these two were an item in the mid-‘80s.
After their four year tumultuous marriage ended, Madonna went on to be a chart topping singer while Sean went on to win two Academy Awards. Divorce was probably a smart move.
Tate Donovan and Jennifer Aniston
The "Friends" star has had a string of Hollywood romances since her split with Brad Pitt. But she had to date a few guys before meeting Mr. Pitt in the first place.
In the mid-'90s these two were engaged. And although fans hoped for a reunion, the "Damages" star says it's a thing of the past.
"It's been 150 years," he jokes. "If you can't bury hatchet in that amount of time something's wrong with you."
Mandy Moore and Wilmer Valderrama
Wilmer had a great time kissing and telling after his year-long relationship with Mandy Moore ended in 2002.
He went on Howard Stern and claimed that he took the young star's virginity, which she later refuted.
She's currently married to Ryan Adams while he still chases around young Hollywood starlets.
Sienna Miller and P. Diddy
In early 2007 some racy pics surfaced of Sienna Miller and P. Diddy getting cozy in a club. Neither of them confirmed that they hooked up, but photogs reportedly saw him leaving her hotel early the next morning.
Where there's smoke...