The band members of 5 Seconds of Summer have been together for four years as of today, Dec. 3!
On Wednesday, the band's oldest and last member to join, Ashton Irwin, got super sentimental on Twitter over their upcoming anniversary.
The sentimental nature continued into early this morning as all the band members celebrated themselves and the fans that helped them get to this point in their careers.
The hashtage "#4YearsOf5SOS" is even trending on Twitter with tons of celebratory tweets from the 5SOSFAM!
"Best 4 years of my entire life," 21-year-old Irwin gushed.
#4YearsOf5SOS best 4 years of my entire life
— Ashton Irwin (@Ashton5SOS) December 3, 2015
The drummer even shared a picture from when they just started out on his Instagram. The nostalgia is in full force--the guys look so incredibly young!
#4yearsof5sos A photo posted by A S H T O N (@ashtonirwin) on Dec 2, 2015 at 11:19pm PST
Irwin then shared a more recent snap and affectionately referred to Luke Hemmings, Michael Clifford and Calum Hood and himself as "Brothers."
A photo posted by A S H T O N (@ashtonirwin) on Dec 2, 2015 at 11:20pm PST
The band's Twitter account added to the celebration with even more photos. This time the band's hilarious nature was visible since they have been known to dress up in ridiculous costumes over the years.
Why do we dress up so much lol #4yearsof5sos pic.twitter.com/pzAswMy1kJ — 5 Seconds of Summer (@5SOS) December 3, 2015
"Happy 5SOS Day," Clifford beamed on his Twitter account.
happy 5sos day :') #4YearsOf5SOS
— Michael Clifford (@Michael5SOS) December 3, 2015
Hemmings, meanwhile, got extra silly by fabricating the story of how they became a band.
"Four years ago Calum got down on one knee and and asked Ashton to join the band, or to marry him," he declared.
#4YearsOf5SOS Four years ago Calum got down on one knee and and asked Ashton to join the band, or to marry him Either way thank you — Luke Hemmings (@Luke5SOS) December 3, 2015
Lastly, Hood, is excited for "many more" years together with Hemmings, Irwin and Clifford.
4 years of 5 seconds of summer. Here's to many more!
— Calum Hood (@Calum5SOS) December 3, 2015
Happy anniversary guys!