Makayla Stephens and her husband, Nick, are not costume people. So when her in-laws were hosting a Halloween party in 2020, the newly married couple didn’t want to dress up.

But they obliged, digging into their closets to find what they could. It was last-minute, and they didn’t have time to buy costumes.

Mrs. Stephens pulled out a pink long-sleeve shirt and white pants. She drew a pink heart around her eye. Mr. Stephens pulled out his only jersey — No. 87 for the Kansas City Chiefs, belonging to Travis Kelce — and put on eye black.

Mrs. Stephens posted a photograph on Instagram, with the caption “I don’t know any world in which Taylor Swift + Travis Kelce would be in the same room together, but apparently in this one they’re married?”

That Halloween went largely forgotten until three years later, when Ms. Swift and Mr. Kelce were, in fact, in the same room — because they were dating.

Mrs. Stephens’s post was shared by a Swift fan account on Twitter, which sent thousands flocking to her Instagram page. Some tagged Ms. Swift and Mr. Kelce in comments. Others joked that Mrs. Stephens was a time traveler or that she had manifested the relationship. Many comments referred to Ms. Swift’s song “Invisible String.”