Ring details, Selena's wedding speech and everything else Taylor Swift just told Jimmy Fallon.

We're in our The Life of a Showgirl era and Taylor Swift is full steam ahead on promoting her 12th studio album.

The singer appeared on The Tonight Show Starring Jimmy Fallon on Monday night and gave us all the goss about everything we've been dying to know.

From the Super Bowl halftime show to her bestie Selena Gomez's wedding, Swift finally put some widespread rumours to bed and shared some sweet insights about her relationship with Travis Kelce.

Here's everything you missed.

First, listen to The Spill unpack every hidden detail from The Life of a Showgirl. Post continues below.

No, she didn't steal Selena Gomez's thunder at her wedding.

The popstar shut down the rumour that she jokingly said to Gomez, "you beat me to the altar" at her bestie's wedding.

"I did make a speech, but I actually made a point not to mention anything about my engagement," she told Fallon.

"No one wants you to be like, 'Hey, I know this is your wedding day but…'" she said, raising her hand to show off her ring. "I was like, 'Don't mention it.'"

Instead, she let Gomez bask in the spotlight, as you'd expect for one's wedding day.

"I got to see her be the most elegant, gorgeous — not only bride but just — vision that I've ever seen in my life," Swift said.

"I've never seen anything so beautiful as her on her wedding day."

Watch a snippet of Swift talking about Gomez's wedding on Fallon. Post continues below.

So, what did she actually say in her wedding speech?

Swift shared it had "some light teasing" and throwbacks to the pair's dress sense in 2008, when they first met.

"It was the year of deep, deep V-necks. It was the year of aggressively colourful skinny jeans…," she said.

"Selena, her favourite outfit back then was a very long tank top, skinny jeans, but a tiny little vest… I always looked like I was late for the cowboy-themed junior prom. So I talked a little bit about 2008, how happy I am for her, how it's been beautiful to get to be a part of her life. But I did not make it about me."

Swift put several rumours to bed on the show. Image: YouTube/fallontonight.

The real reason she won't play the Super Bowl.

Fallon asked Swift about the rumour she'd turned down an offer to play the Super Bowl because the NFL wouldn't let her own the performance footage.

Swift said her team has a good relationship Jay-Z's (as his Roc National company partners with the NFL to make the final decision on Super Bowl halftime show performers).

"Jay-Z has always been very good to me. Our teams are very close," Swift began.

"They sometimes will call and say how does she feel about... and that's not an official offer or a conference room conversation.

Swift said there's one main reason she doesn't fancy taking the stage at the halftime show.

"We're always able to tell him the truth, which is that I am in love with a guy who does that sport on that actual field."

Ultimately, the stress of watching Kelce play is too much.

"That is violent chess. That is gladiators without swords. That is dangerous," Swift said.

"The whole season, I am locked in on what that man is doing on the field. Can you imagine if he's out there every single week putting his life on the line, doing this very dangerous, very high-pressure, high-intensity sport, and I'm like, 'I wonder what my choreo should be. I think we should do two verses of 'Shake it Off' into 'Blank Space' into 'Cruel Summer'."

She added: "This is nothing to do with Travis, he would love for me to do it. I'm just too locked in."

Swift says she's too 'locked in' when Kelce is playing to consider playing the Super Bowl. Image: Getty.

Behind the bling.

Swift also shared some of the backstory behind her dazzling engagement ring.

Her fiancé custom-designed her ring with "this amazing jeweller", Kindred Lubeck.

As much as she adores Kelce, gushing that he's her "favourite person I've ever met", what the ring "represents" is equally important to her.

"The fact that this is the person I get to hang out with every day forever, that's the whole thing of it, that's the win, and this represents that," Swift said.

The singer took us back to the moment Kelce popped the question, saying it was the "best possible case scenario".

Her flower-filled backyard proposal, which Kelce had set up in his garden while they recorded his podcast New Heights, was like a "secret garden".

Swift's dazzling ring. Image: Instagram/taylorswift.

Appearing on UK radio show Heart Breakfast on Friday, Swift said she first showed Kelce Lubeck's designs 18 months ago.

"I just thought her stuff was so cool," she said.

"I had shown him a video like a year and a half ago, and he was just paying attention to everything, it turns out, because when I saw the ring I [gasped] ... I was like, 'I know who made this, I know who made this,' and also, 'You listen to me!'"

Ed Sheeran and the engagement.

It turns out, Sheeran really did find out about Swift's engagement from her Instagram post. But the singer had a good explanation for that.

"He doesn't have a phone," Taylor stressed. "He doesn't have one that works."

She said Sheeran was

She explained that to get in touch with him you need to jump through a series of hoops: including emailing him and getting him to source an iPad on which they can converse.

Kelce proposed in a 'secret garden' set up in his backyard. Image: Instagram/taylorswift.

Writing 'Wood'.

Sadly, the infamous redwood tree Ariana Grande tweet did not get a mention here, but Swift did explain how her spicy track, which fans think references Travis Kelce's 'manhood' came to be.

"I brought this into the studio and I was like, 'I wanna sort of do a throwback kind of timeless sounding song,'" she said.

"I had this idea about, 'I ain't gotta knock on wood.' And it would be all these superstitions."

It started "in a very innocent place", she said.

"I dunno what happened, man," Swift laughed.

"I got in there, we started vibing and I don't know. I don't know how we got here, but I love the song so much."

Feature image: YouTube/fallontonight.