"I’ll dress up as Katy Perry and then you and I can pretend to be together!," one person wrote. "TO HIS LEFT 👏👏👏," another person commented, referring to Bryan Gaw, famously known as 'Left Shark ' in Perry's halftime show performance.

Justin and his wife, Sophie, announce their separation after 18 years of marriage.

“the one that got away,” the musician wrote in his caption, playfully referencing Perry’s 2011 hit of the same name.