A fan who attended one of Taylor Swift's Eras Tour concerts used a friendship bracelet to reveal a wonderful secret to her sister.

"A year ago today, I got to share my favorite secret with my favorite sister," TikTok user @bekahbaggins wrote in a video that has been viewed over 188,000 times as of publishing.

The video shows Bekah, 27, handing her sister a homemade bracelet at Swift's concert in Minneapolis that reveals she's pregnant.

Her sister looks stunned as she reads what it says: "Octagon."

"Are you serious?" Bekah's sister shouts, hugging her.

Watch the heartwarming moment, below:

In a separate video, Bekah explained the meaning of "octagon," saying "it's a bit of an inside joke with my family."

"Essentially, the story goes that I have four older siblings, and when I was born, I believe it was really early in the morning. So my dad called my aunt to tell her, 'Hey, you're an aunt again,' and she was very tired and very out of it, and she could not comprehend why someone was calling her at that hour of the morning to call her an 'octagon,'" she explained.

READ MORE: Ick! Taylor Swift Coughs After Swallowing Bug Live on Stage

"Since one of my brothers already has kids, I figured 'octagon' would be a good way to tell her she's an aunt again," Bekah noted.

The TikTok user also admitted the bracelet was "a bit of a gamble," as she "wasn't sure if that story lived rent-free in her head like it did in mine."

Watch below:

SPOTTED: Celebrities Having a Blast at Taylor Swift's Eras Tour

Let's take a look at all of the famous Swifties that were spotted in the stands.

Gallery Credit: Danielle Kootman