This kiss-off to a former boyfriend was written and co-produced by Greg Wells (Mika, Natasha Bedingfield). He also performed similar duties for "Fingerprints" on the same album.
In an interview for her London Live! concert special, Perry said that this song was about the "emo, indie-rocker boys that borrow your makeup and wear your outfits." Said Perry, "I'm still making out with you, and it's kind of an interesting situation that you like me, but you in another life were probably not on my team."
asked Perry if she felt this song enforced a negative stereotype. The Los Angeles-based singer/songwriter replied: "Every time I play that song, everybody has come back laughing. I'm not the type of person who walks around calling everything gay. That song is about a specific guy that I used to date and specific issues that he had. The song is about my ex wearing guyliner and taking emo pictures of himself in the bathroom mirror. The listeners have to read the context of the song and decide for themselves."
This originally was the title track of an EP released in 2007. It got an unsolicited critical boost from Madonna, who referred to the tune as her current ipod favorite. Perry said "I'm still floored by that. It's like, you're Madonna - you don't have time to be listening to my songs!" The EP also featured a club remix of the song by DJ/producer Junior Sanchez (Madonna, Shakira).
Perry told the Santa Barbara Independent June 24, 2008 about the first time she heard this song on the radio: "I was on my way, running an errand in Hollywood, and I turn on my radio and I heard them play the Catch of the Day on (LA based station) KROQ. And it was a song from my EP [called] 'UR So Gay.' I literally almost ran into the center divider. I was like, 'Not only am I hearing my song for the first time, but I'm hearing my song on KROQ,' which is so cool. And I just heard that KJEE added the song, too, and I'm like, 'Yeah, hometown hero, let's go!'"
The video starred a crew of plastic Barbie and Ken knockoffs and clever, low-budget miniature props. On her MySpace page Perry blogged about the creation of the video: "My friend Walter and I were chatting about wanting to do a little video for it a few weeks ago and I said let's use BARBIES! (they're not official barbies, thank the law!) Walter and team spray painted, wall papered and even LEATHERED the miniature set… I hope you guys pick up on the funny little details… like totally awesome rocker dude. hee hee. We had fun making this."
Years after releasing this song, Perry became an activist for LGBTQ rights, and in 2017 she was given the National Equality Award from the Human Rights Campaign
Said Perry: "There's no other community that has done more to shape who I am today, and there is no other community that I believe in more than you. You don't get to choose your family, but you can choose your tribe. Many of the people I work with, trust and admire belong to the LGBTQ community, and without them I'd be half of the person I am today. My life is rich in every capacity because of them. They are trusted allies that provide a safe space to fall and to make mistakes. These are the people I hold dear."