5 Seconds of Summer Share Flashback Photo From 3 Years Ago During O2 London Concerts

5 Seconds of Summer light up the stage during their concert at the O2 Arena in London, England on Saturday night (April 9).

The guys — Michael Clifford, Ashton Irwin, Luke Hemmings, Calum Hood — got together quickly backstage for a group photo, which they all shared later on in a collage with an old pic.

“At the London O2, 3 years ago, tonight is a special night too us, can’t believe how far we’ve come with you all xx,” Ashton captioned.

Calum added, “3 years ago, supporting at the o2 arena. Yesterday, headlining at the o2 arena.”

55+ pics inside of 5 Seconds of Summer…