Avril Lavigne sang Sk8er Boi at Taylor Swift's wedding.

Former WWE and NFL star Pat McAfee was in attendance at Madison Square Garden on July 3 to see Taylor and her husband Travis Kelce tie the knot, and has opened up about the musicians who got up to treat guests to some surprise performances.

Speaking on The Pat McAfee Show, he said: "Stevie Nicks played, Taylor was up with them, obviously. Avril Lavigne -- I don't want to give away too much. But it was the greatest night of all time."

In another episode, he added: "I guess me saying Avril Lavigne played 'Sk8r Boi' was the first time that it came out. But she was awesome."

Pat also revealed that the atmosphere was kept relaxed, with each musician getting called up by the previous performer.

He said: "And to be clear, those musicians... one would just call out the other, and then they would come up and they would just do their s***."

On Monday's (13.07.26) episode of his daily talk show, Pat offered a bit more insight into the newlyweds' special day.

He said: "That was the most spectacular evening I have ever been a part of ...

"I'm sure there was something that I agreed to not talk about, but from the things that I've been reading about other people talking about it like kinda sorta cause there were no phones in there. There is no notes section, no writing or anything so it's literally all just memory."

He added: "[Taylor is] one of the greatest creators that the world has ever seen. She puts on stadium shows all around the globe.

"She has to entertain people that are 90 and also 15. Think about her brain going to her dream wedding and then Travis Kelce's energy in the middle of it ...

"I don't want to give away too much but it was the greatest night of all time. My wife and I had a blast. They absolutely showcased that they are in love, it was very obvious."

And he defended the couple from criticism of their lavish nuptials.

He added: "So anybody that's saying anything negative about that place … now granted, shutting down a pulsing city and that whole thing, you guys can have your thoughts on that.

"The event itself was like the most spectacular grand thing I've ever seen in my entire life ...

"Just know anything negative that has ever been thought about the event … me and my wife understood that we didn't understand why we were invited but we were very excited and thankful and we let them know.

"We had a blast, it was incredible. Everything was just obviously top of the line. And Travis Kelce is very much in love, seems very happy."