Taylor Swift's new song 'Would've, Could've, Should've' gets fans fired up over John Mayer again

John Mayer predicted he'd be trending after the release of Taylor Swift's Midnights.

Swift's 10th studio album has dropped and fans are certain she has a new "Dear John" song. On the Midnights (3am Edition), there's a track 19, which the internet believes is about Mayer, who Swift briefly dated when she was, yes, 19.

In the song "Would've, Could've, Should've," Swift sings about being 19 and in a relationship with a poisonous "grown man" — Mayer was 32 at the time — who later dismissed her as "a child." She said she "danced with the devil" and called him "a crisis of my faith." She said he made her "feel important," but then he "tried to erase us."

It still gets under skin her, she sings: "I regret you all the time" and "I fight with you in my sleep," adding, "Living for the thrill of hitting you where it hurts." And, perhaps the most scathing line, "Give me me back my girlhood, it was mine first." (See the full lyrics via Genius.)

Twitter has been on fire since the song dropped. One person wrote, "John Mayer was sleeping peacefully but was awoken at 3am with a chill down his spine."

Here are some others:

Swift's previous song "Dear John" on Speak Now, was a not-so-subtle breakup anthem about the "Your Body Is a Wonderland" singer. The pair dated in 2009 after collaborating on his song "Half of My Heart," but things had soured by early 2010. When Speak Now was released in October of that year, she sang: "Dear John, I see it all, now it was wrong," she sang at the time, "Don’t you think 19 is too young / To be played by your dark twisted games, when I loved you so? ... Maybe it's you and your sick need to give love then take it away / And you'll add my name to your long list of traitors who don't understand / And I'll look back and regret how I ignored when they said 'run as fast as you can... All the girls that you've run dry have tired lifeless eyes /'Cause you burned them out."

Mayer later said he felt "terrible" about the song, but added that it was a "lousy thing [for Swift] to do. I never got an email. I never got a phone call. I was really caught off guard." He also called it "cheap songwriting." Nonetheless, the next year she was reportedly behind his 2013 song "Paper Doll" which basically pulled "you're just a crazy lady" card. He sang, "You're like 22 girls in one. And none of them know what they're running from. Was it just too far to fall for a little paper doll?"

Mayer's dating reputation preceded him in that era. He was linked to Jennifer Love Hewitt, Minka Kelly, Jessica Simpson, Jennifer Aniston and, later, Katy Perry. His boorish behavior was well-documented. (See: Simpson's book. Flashback to: Him having an impromptu sidewalk press conference after breaking up with Aniston.) In 2016, he admitted that he got "caught up" in his celebrity and said there was a "humility in knowing that you’re not popular to the point where people are following you around anymore."

Last year, when Swift re-released Red, including an extended version of "All Too Well," which was thought to be about her ex Jake Gyllenhaal, both Gyllenhaal and Mayer faced backlash from Swifties over the resurfaced narrative of a woman (aka Swift) being wronged. Mayer responded to hateful messages, including death threats on social media.

None of that kept Swift up at night. Around the time, she told Seth Meyers she didn't care much about how her exes feel about being mentioned in her songs, saying, "I haven’t thought about their experience, to be honest."

Midnights, out now chronicles Swift's "journey through terrors and sweet dreams" and "13 sleepless nights" of her life. There are actually 20 tracks in total on the extended album. On the album she does also sing about love, specifically her six-year romance with actor Joe Alwyn, which she keeps out of the spotlight. In "Lavender Haze" she sings about rumors about them: "I'm damned if I do give a damn what people say/ the 1950s s*** they want from me/ I just wanna stay in that lavender haze. All they keep asking me is if I'm gonna be your bride/ the only kinda girl they see is a one night or a wife."