"Bad Blood" singer Taylor Swift could soon find herself on the outs with girl squad member Kendall Jenner.

According to Hollywood Life, Jenner once promised Swift she would never again become involved with Swift's ex-boyfriend Harry Styles, prompting many to speculate that news of Jenner's tropical island vacation with the One Direction singer would not sit well with her pal.

Word is Jenner and Styles spent part of the recent holiday season vacationing in Anguilla, where they were spied having a romantic dinner together and snuggling up on a yacht.

Swift is rumored to have received the news from a mutual friend and is reported to have been in total shock.

"Taylor and Kendall actually bonded over dissing Harry and comparing notes on him," a source said. "The fact that Harry and Kendall are celebrating New Year's Eve together is beyond weird to Taylor. She really can't trust anything that Kendall tells her, not now that she's back with Harry."

Swift and Styles split in 2013 in a breakup that turned nasty amid allegations the latter was unfaithful.

"[Harry] was all, like, 'You're amazing -- I want to be with you,'" a source said back then. "'I want to do this.'"

But over time, reports are Swift came to fear Styles wasn't to be trusted and his partying lifestyle was more than she could handle.

"[He] disappeared one night and after that it was like he just didn't want to keep going," a source added.

At one point, a picture of Styles making out with another girl was posted online, and that marked the beginning of the end for the once happy couple.

Although Swift tried forgiving him and giving him a second chance, a source admited at the time she "felt like he was looking at every girl."

Soon after that, the two parted ways for good.