By Lisa Respers France, CNN

(CNN) -- Their "Love Story" started at a Taylor Swift concert so it just made sense that they would get engaged there.

The singer posted a series of photos Friday on her Instagram showing her in between a fan who proposed to his girlfriend during the meet and greet at her Philadelphia concert.

"They walk into the meet and greet and he says, 'We met 5 years ago at the Red Tour' and then..... ," The caption read with Swift jokingly referring to herself as #thirdwheel.

Swift didn't identify the couple but the Twitter account @TSphilaPROPOSAL documented "Anthony + Stephanie - I PROPOSED IN FRONT OF TAYLOR SWIFT 7/13/18 DURING #RepTourPhilly."

According to a tweet on the account, Anthony had been planning the proposal since June.

"I want to give my girlfriend the proposal of her dreams! Help me spread the word so Taylor can see this," the tweet said. "I know Taylor can make this night unforgettable. #ReputationTourPhillyProposal @taylorswift13 @taylornation13."

There is also a tweeted photo of the couple on the fateful day they met five years ago.

The pair are such die hard Swifties that they returned Saturday for her second night concert in Philadelphia -- this time wearing T-shirts featuring their proposal pics with the singer.

"We are back... as an engaged couple! #RepTourPhilly @taylornation13 @taylorswift13," a tweet featuring the photos read.