John Mayer made it very clear to Rolling Stone that country crooner Taylor Swift did him wrong when she penned the song “Dear John.” Photo courtesy of John Mayer official Facebook fan page.

John Mayer made it very clear to Rolling Stone that country crooner Taylor Swift did him wrong when she penned the song Dear John. So when the two had a run-in while out in West Hollywood, of course, it would be awkward.

On Tuesday, Swift hit up West Hollywood's Tower bar. Little did Swift know, a Mayer run-in was looming.

When the 22-year-old entered the hotspot at the Sunset Tower Hotel on Tuesday night, it was drama central when she saw Mayer sitting at a table nearby, according to the New York Post's Page Six.

Taylor very visibly - in front of the entire restaurant - demanded to be moved to the other side, a source said. The bar's usually an oasis of calm and privacy for celebrities and power players, but this was drama central.

The next day, Mayer's Rolling Stone interview was published for the entire world to see. He described to the pop culture mag how Swift really humiliated him with her song Dear John.

It made me feel terrible, John Mayer says in the new issue of Rolling Stone. Because I didn't deserve it. I'm pretty good at taking accountability now, and I never did anything to deserve that. It was a really lousy thing for her to do.

Mayer and Swift were briefly linked in May 2009, according to MTV, but allegedly split in June 2010, before the October 2010 release of her Speak Now album. Prior to Swift, Mayer had been in a year-long relationship with actress Jennifer Aniston, which ended in March 2009. Swift had been linked to Joe Jonas and Taylor Lautner.

I never got an e-mail. I never got a phone call, Mayer says. I was really caught off-guard, and it really humiliated me at a time when I'd already been dressed down. I mean, how would you feel if, at the lowest you've ever been, someone kicked you even lower?

John Mayer and Taylor Swift perform during Z100's Jingle Ball concert at Madison Square Garden in 2009. The two sang together on Mayer's song, Half of My Heart. Photo courtesy of Reuters.

In Dear John, the country singer croons: Dear John / I see it all, now it was wrong / Don't you think 19 is too young to be played by your dark twisted games, when I loved you so? / I should've known / All the girls that you run dry / With tired, lifeless eyes / Cause you burned them out / But I took your matches before fire could catch me / So don't look now: / I'm shining like fireworks over your sad, empty town.

When Rolling Stone asked his thoughts on the line, Don't you think I was too young to be messed with? Mayer says, I don't want to go into that.

As for Swift, her friends have got her back.

I can't believe he is trying to play the victim! a source told Us Weekly. John was a player and treated her like s--t, another source added. He looked at her as a conquest. Taylor is going to think even less of him now!

John Mayer does not agree with Swift's writing process.

I will say as a songwriter that I think it's kind of cheap songwriting, he tells Rolling Stone. I know she's the biggest thing in the world, and I'm not trying to sink anybody's ship, but I think it's abusing your talent to rub your hands together and go, 'Wait till he gets a load of this!' That's bulls--t.

However, Mayer reportedly uses his own love troubles as lyrical inspiration, as well. Shadow Days, off his new album Born and Raised, is supposedly about ex Jennifer Aniston, according to Us Weekly.

Mayer sings: You find yourself alone. . . I found myself in pieces / On my hotel floor/Hard times help me see / I'm a good man with a good heart / Had a tough time, got a rough start / And I finally learned to let it go.

A source told the magazine, He wrote the song as a farewell letter knowing [Jen] would hear it. Ultimately he's done a lot of self reflection though and it he realizes they weren't right for each other.