"I am blessed to work with incredible artists @rihanna @taylorswift13 thank you!!!" Harris, whose real name is Adam Wiles, wrote.
The message was in response to a tweet from a "Rihanna Facts" account that noted "'This Is What You Came For' is the only song released this Year to be certified 2x platinum in the UK congrats @CalvinHarris and @rihanna."
Fans immediately weighed in, writing things like, "How to kill someone, a tutorial by Calvin Harris," "Adam wtf," "I AM LITERALLY SHAKING," and "WAIT, are you and Taylor friends now?!?!" Others suggested he was just being "polite," with one fan tweeting, "You are a better person than I am, Calvin!"
As many fans of the former couple may recall, Swift's team revealed that she secretly wrote the catchy tune using the pseudonym Nils Sjoberg following their June split. The song was released on April 29 (when Swift and Harris were still an item), quickly reaching No. 1 on Billboard's Dance/Electronic category.
"During their relationship, Taylor wrote the song, sat down at a piano and did a demo into her iPhone," a source confirmed to ET at the time.
The Nashville native sent the song to Harris, who apparently loved it. "They both went into a studio and did a full demo with Taylor on vocals and Calvin doing the beat," the source added. "They both knew the song would be a hit, but Taylor wrote it for Calvin and [they] both agreed it was a bad idea to let the world know they collaborated as a couple -- it would overshadow the song."
Although Harris wasn't happy to see Swift move on with Tom Hiddleston so quickly -- who could forget his infamous Twitter rant? -- the Scottish DJ's most recent tweet seemingly proves they're on slightly better terms.
Swift, who has since split with Hiddleston after three months of dating, performed at the Formula 1 U.S. Grand Prix in Austin, Texas, last month, marking her first performance in a year. At one point in the show, she belted out "This Is What You Came For" as the crowd erupted in cheer.
"As a songwriter, the most rewarding feeling in the world is writing something and then having a crowd sing it back to you, because they know the words. It’s the coolest thing in the world," she said onstage. "And I've never played this song live before, but you know it. Maybe you could sing along, and then I could get to know what that feels like to hear it sung back to me."
As for when we'll get a new album? Fans will patiently have to wait for the GRAMMY winner's confirmation. Swift's pal, Gigi Hadid, accidentally let the exciting news slip that new music is on the way when ET caught up with her at New York Fashion Week in October.
"She's obviously such a great friend, and you know she is starting to go back to work in the studio again, and really made time to be here for me, and I am so grateful for that," the 21-year-old model said at the time.