This empowering breakup song was written by Little Mix with Iain James and Camille Purcell. The UK songwriters also co-penned together the Get Weird singles "Love Me Like You" and "Hair," as well working with different songwriters on several other of Little Mix's hit tunes.
The song was produced by Norwegian duo Electric, who previously worked with Little Mix on their "Black Magic" single.
Little Mix's Jade Thirlwall said: "'Shout Out To My Ex' is a song that we're sure loads of people can relate to. It's all about moving on after a relationship ends to bigger and better things, and leaving the past where it should be."
In 2015 Perrie Edwards and Zayn Malik called off their engagement, after the former 1D star allegedly dumped the Little Mix songstress via text, before moving on to supermodel Gigi Hadid. The lyrics for this ex-blasting song appear to contain several disses at Malik including claims that Edwards had been faking orgasms when they were together.
I hope she gettin' better sex, Hope she ain't fakin' it like I did, babe.
Asked by The Sun whether Malik had been given heads up about the brutal takedown, Little Mix's Jesy Nelson replied: "We don't think he deserves a warning! He'll just have to wait to see."
Many listeners have pointed out the song's musical and thematic similarities to G.R.L.'s 2014 single "Ugly Heart." The American girl group themselves tweeted "ShoutOutToUglyHeart."
Asked about the likeness between the two songs during a Belgian radio, interview Jade Thirlwall said: "Every song is going to have a similar chord sequence, slightly similar lyrics and melodies. It happens all the time. It doesn't mean that they're not both incredible songs."
"I think maybe because it was a girl band as well," she added. "I just think people like to have something negative to say."
This was Little Mix's fourth #1 single in the UK following "Cannonball" "Wings" and "Black Magic."
Perrie Edwards explained why the quartet recorded the song to Pop Crush:
"I think when you go through a breakup, the first initial thing you do is put on music. I think everyone can relate to music. It doesn't matter who you are in the world, where you are in the world. Your initial reaction is to listen to really sad songs and get upset and get emotional. But I feel like we're kind of missing that anthemic, I don't really care anymore song that makes you feel amazing and makes you feel empowered and it's inspirational. And everybody in the world can relate to it, because everybody's got an ex, and everybody needs a little pick me up I think, which is nice, so that's why we did it. We want everybody to feel great about themselves."
The original lyrics were a lot more sweary and appear to reference Gigi Hadid, the model girlfriend Zayn Malik hooked up with after dumping Perrie Edwards.
Heard he been f-----g some model chick Yeah that s--- hurt I'll admit, but f--- that boy I'm over it
When asked about the earlier version by News.com.au, Perrie said: "We had to make it clean. We didn't want to have the parental advisory sticker on our albums and singles. Even though our fans are our age, 20 or over 18, we still have a lot of young fans. But it does feel good to swear, doesn't it?"