Katy Perry threw some serious shade at Taylor Swift as she weighed into her foe's spat with Calvin Harris.
A long-time rival of the I Knew You Were Trouble hitmaker, Katy kept it elegantly sly and sassy with a couple of sublime tweets, posted after Calvin hit back at his ex-girlfriend Taylor in a tirade of messages.
Things became messy for former flames Taylor, 26, and Calvin, 32, on Wednesday when the US singer revealed she had secretly written his new hit with Rihanna, This Is What You Came For.
Hitting back at his ex-love of 15 months in a series of heated tweets, Calvin dubbed her 'hurtful' and accused her team of trying to make him 'look bad', while also referencing her surprisingly speedy new romance with actor Tom Hiddleston.
Calvin also mentioned Katy herself, noting her ongoing feud with Taylor, writing: 'I know you're off your and need someone new to try and bury like Katy ETC but I'm not that guy, sorry. I won't allow it.'
Katy, 31, clearly couldn't hold back as she launched a subtle but brilliant attack on Taylor - with whom she's had beef for years, and who also dated her ex-boyfriend John Mayer - retweeting one of her own posts from last year.
Keeping it simple, and adding no further explanation, the original May 2015 message read: 'Truth, the ultimate truth teller.'
Time, the ultimate truth teller.
-- KATY PERRY (@katyperry) May 9, 2015
Prior to this, she shared a sassy eyebrow-raising gif of presidential candidate Hillary Clinton, again without a caption.
In typical style, fans - who no doubt remember the time Katy dubbed Taylor 'Regina George in sheep's clothing' - went wild for her not-so-cryptic messages, honouring the Firework singer with a series of tweets full of praise.
-- Ágatha *?? (@oneofthebxys) July 13, 2016
-- marcela (@marcelamribeiro) July 13, 2016
Watch out for the Regina George in sheep's clothing...
-- KATY PERRY (@katyperry) September 9, 2014