Of all the songs Taylor Swift could have chosen to dance along to, it happened to be ex boyfriend Calvin Harris's This Is What You Came For - the single at the centre of their post-breakup argument.
On Friday night at the end of the Tommy Hilfiger fashion show, the pop star shared a video of her dancing around to the hit song in the Front Row with friend Martha Hunt.
Is it a dig at Calvin - or an olive branch?
In July, Taylor's team suddenly revealed that she was behind Calvin's hit: "Taylor Swift wrote This Is What You Came For under the pseudonym Nils Sjoberg."
This left Calvin a little upset.
He tweeted: "And she sings on a little bit of it too. Amazing lyric writer and she smashed it as usual."
But then in a series of increasingly angry Tweets, he complained: "I wrote the music, produced the song, arranged it and cut the vocals though. And initially she wanted it kept secret, hence the pseudonym... Hurtful to me at this point that her and her team would go so far out of their way to try and make ME look bad at this stage though."
He accused her of "trying to tear your ex bf down for something to do".
The Scottish DJ now admits he should not have lashed out in the aftermath of the relationship.
He told GQ magazine: "It was completely the wrong instinct. I was protecting what I see as my one talent in the world being belittled.
"It felt like things were piling on top of me and that was when I snapped. I'm not good at being a celebrity, but when it ended, all hell broke loose.
"It clearly wasn't right, so it ended, but all the stuff that happened afterwards..."