Taylor Swift kisses and tells. But she never reveals with whom, leaving it up to her throng of fans to muse about and come up with fan fiction stories to fill in those information gaps in her songs. Swift's new single 'We Are Never Ever Getting Back Together' is most definitely about an ex-boyfriend. She said it in her podcast last night and in an interview with ABC. She didn't say who inspired the song, but she did say how!

Swift revealed to 'Nightline' anchor Cynthia McFadden exclusively that the song is absolutely based on fact and on her life.

"Writing 'We Are Never Ever Getting Back Together' was one of the most hilarious experiences I have ever had in the studio because it just happened so naturally," Swift admitted. She wrote the song with Max Martin and Johan Shellback after a friend of her ex's walked in and began talking the talk.

Swift continued, "He starts talking about how he's heard we were getting back together and that was not the case. When he leaves, Max and Johan are like, 'So what's the story behind that?' And so I start telling them the story of break up, get back together, break up, get back together, just, ugh, the worst." She even sings about how all that reuniting and splitting is exhausting in 'WANEGBT!'

After Swift relayed the break up story, Martin interjected, saying, "This is what we’re writing. We’re writing this song." Swift picked up the guitar and just started singing the hook. "It just happened so fast. It was so much fun," she said.

Fun if you are a teenage girl nursing heartbreak. No so much if you've dated Swift and it's about you.

In other Swift news, she will perform on 'Good Morning America' on Oct. 22 and Oct. 23. They'll be the first live concerts for 'Red,' the new album dropping Oct. 22.

Watch Taylor Swift Talk About Song Inspiration on ABC