1. The first time they sang together as a group.
Perrie Edwards, Jesy Nelson, Leight-Anne Pinnock, and Jade Thirlwall originally auditioned for X-Factor UK as solo artists in 2011. After not making it to bootcamp, they gave them the option of being part of a group and they accepted, but they weren't put together at first. Jade and Leigh-Anne were with another girl in a group that they called Orion, while Perrie and Jesy where paired up with other two girls and formed Faux Pas. Both groups failed to make it to bootcamp, but just as they thought everything was lost, Saint Kelendria Rowland decided to take two girls from each group and created a new one: Rhythmix. Because they were part of other groups when they sang in front of the judges, their first time singing together was at the Judges House in front of Tulisa Contostavlos and Jessie J. Obviously, they made it through to the live shows.
Fun Fact: If you watch videos of them before they were put together, you can see that they were already talking to each other. When they were in a room after being eliminated as solo artists, the four of them were sitting together talking and they were even interviewed together. It was a sign, to be honest. Also, this was the third time that Jade Thirlwall auditioned for the show. The other two times were in 2008 and 2010, and both times she was eliminated at bootcamp. She even appears on a video with Harry Styles from her time on the show back in 2010, which was the year when One Direction got formed and competed.
2. First group to win X-Factor.
On 11 December 2011, Little Mix, originally called Rhythmix, became the first group ever to win X-Factor, making Marcus Collins the show-runner of the eighth series.
Fun Fact: They had to change the name of the group to Little Mix because Rhythmix was the name of a children's music charity and Simon Cowell failed to trademark the name. Their first single was called “Cannonball”, and was released digitally the same night they won.
3. Little Mix sing Opera.
During the backstage of T4 of the Beach, Perrie started singing opera, joined almost immediately by Leigh-Anne, who started signing along with her. Once Leigh-Anne realized that she couldn't reach the same notes as Perrie, she gave up and flipped her the bird. Perrie was then joined by Jesy and Jade.
Fun Fact: The song that they're singing is “Pie Jesu.”
4. The Lie Detector.
On 7 November 2013, the girls went to the radio show In:Demand, and Jade was connected to a lie detector. The other girls gave the host some information without her knowing it, which was going to help him ask her questions. Some of Jade's answers included an explanation as to why the girls call her Poopy (watch the video if you want to know), a confession about not wearing underwear that day because she forgot to pack it, and her love for FaceTime, which was implied that she used for naughty things.
Fun Fact: Back when the interview took place, Jade was dating Diversity's Sam Craske. It's obvious that the girls wanted her to say out loud that she used FaceTime to have sex with her then boyfriend when they were overseas, but she never admitted it, even though it was pretty much confirmed/implied by the rest of the group. When the host asked her if she used the application with her family Jesy said “I hope not”, because clearly Jade wasn't using it for innocent activities.
5. Little Mix do the accent challenge.
Earlier last year, the girls were at some YouTube channel called You Generation, in which they did two challenges: chubby bunny, and an accents one. When they were doing the second one, Jesy was possessed by some demon while trying to do a Jamaican accent, giving us the legendary BALEGDAH. We also got Jade failing while trying to do a Spanish accent, and Leigh-Anne sounding like someone from Sparta instead of Russian.
Fun Fact: A video of Jesy saying BALEGDAH has over 430,000 notes on Tumblr.
6. Five questions for Jesy Nelson.
On 13 May 2014, Little Mix played “5 Questions For” at Capital FM. During Jesy's segment, she was asked about the strangest animal that she had ever ridden. After not knowing what to say for a few seconds, the rest of the group started shouting from the background “Jordan!”, referring to Diversity's Jordan Banjo, Jesy's ex-boyfriend. While everyone laughed, Jesy took the opportunity to curse at them.
Fun Fact: Jesy was still dating Jordan when this interview happened.
7. Plank all over me.
On 19 October 2014, Jade and Jesy planked over Matt Edmondson on BBC Radio 1. Jade stopped at 1 minute and 26 seconds, and she struggled while doing it. While she was being interviewed, because that's part of the game, she said that, if she were a Disney character, she would be Princess Jasmine, and that she wasn't going to be the first member of the group going solo. Jesy stopped at the 3 minutes mark, and while being interviewed she said that if she weren't part of Little Mix she would like to be an actress. She also said that, if she could be in any other girl band for a day, she would be on Destiny's Child.
Fun Fact: Jesy broke a record during the game for planking over Matt during 3 minutes.
8. Little Mix resquests a stripper.
Apparently, weird things happen whenever the girls go to In:Demand. In this interview, which took place on 10 June 2015, Jade wanted a man, even though she said it wasn't true, so they brought a stripper for her, and hilarity ensued. The man, named Conna, took off his shirt, put lotion on his chest, and almost took off his pants while the girls encouraged Jade to touch him and everyone died of laughter. At some point, Conna pushed Jade's head down to make it seem like she's giving him oral and the faces the girls made are priceless.
Fun Fact: In another video of the same interview, a puppy named Tallulah was brought to the girls because they had requested it, and they played with her for a while.
BONUS: Compilation of some of Little Mix dirtiest moments.
Highlights of the video:
— Jesy saying that Leigh-Anne puts chocolate ice cream on her boyfriend's dick.
— Perrie holding a dildo.
— Jesy saying that Leigh-Anne likes cracking whips in the bedroom.
— Jesy saying that Jade likes getting naked in front of her now ex-boyfriend (Sam Craske) on FaceTime.
— Jesy saying that, if she had to, she would walk-in on Perrie and Zayn having sex to put a condom on his dick because she thought, back then, that Perrie was going to be the first one to get pregnant.
sources: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10