Taylor Swift laughed so hard while singing a song that's allegedly about Kanye West

Nobody's accusing Taylor Swift of not having a sense of humour.

At this stage in the superstar's Eras Tour leg in North America, you've probably heard that Swift has a regular setlist, and that she fits in two new surprise songs at every tour date.

During a recent stop in Seattle, the singer delighted fans by adding "This Is Why We Can't Have Nice Things" to the setlist, a song off her 2017 album Reputation. Both the song and the album are thought to be largely influenced by Swift's feud with Kanye West.

In the original recording of the song, after rattling through some pretty unforgiving lyrics, Swift sings "forgiveness is a nice thing to do," before pausing, then laughing hysterically and saying: "I can't even say it with a straight face."

Well, while performing the song, Swift launched into a dramatic cackle, which appeared to originally be her acting, but which came out so loud and full of feeling that it ended up making her crack up for real. She then continued to giggle, as captured by a fan's TikTok of the scene, before quickly saying that spoken line, then launching back into the chorus with even more force.

The TikTok user who posted the video captioned it: "SO FUN SO FUN SO FUN!!!!"

Swifties took to the comments to express their happiness over watching this clip, with one person writing: "This is my new favorite clip of Taylor from the tour"

Another person said: "Her cackle is EVERYthing"

"Just the way she interacts with her HUGE crowd makes me even more in love with her!" said a third commenter.

Swift and West first had a public spat when the latter took to the stage as the former was accepting a VMA in 2009. He said: "Taylor, I'm really happy for you, Imma let you finish, but Beyoncé had one of the best videos of all time."

The two publicly reconciled but, in 2016, the rapper released a song containing the line: "I feel like me and Taylor might still have sex / Why? I made that b**** famous"

He claimed that he had asked Swift for permission to use the line, but Swift denied that he had. Then in July 2016, Kim Kardashian — who was married to West at the time — released footage of the alleged phone call between West and Swift, during which he claimed to have asked for permission. In it, Swift appears to give West permission to call her "b****" — though a rep for the popstar said she wasn't aware of the actual lyric, according to People.

After that, Swift lay low for a while until she released Reputation, many of whose lyrics centre around revenge. Make of that what you will.