To her mind, she fairly writes songs about them.
"This is the third album that I've been doing this, so they had fair warning at this point," the 20-year-old country superstar told David Letterman on his CBS Late Show Tuesday.
She's issued this caution sign before. Last week, in response to the news that that her new album, Speak Now, is packed with tunes about her roller-coaster relationships of the past two years – which saw her linked to Taylor Lautner and John Mayer – Swift told PEOPLE: "This is album No. 3, so I figure that these people have had fair warning."
Though sending messages to exes is not her main point, she told Letterman. "One of the things I'm really proud about on this CD [is] I wrote it by myself without any co-writers."
She added, "For two years I was living life and I kind of write it real time. I wrote these moments in time. The songs are written when I'm feeling what it is I'm discussing in the song. It's all kind of done when it's happening."
She also demonstrated an uncanny ability to speak Japanese, having memorized the words and which she said she used to advantage during a recent concert in Osaka. But that's not all that impressed Letterman.
"Please don't take this the wrong way," the show host told Swift, "but you smell like expensive wood … It's good. Believe me, it's very good ... very subtle, very pleasing."
She said it may have something to do with the fact she grew up on a Pennsylvania Christmas tree farm.