It was released April 3, 2007, to the United Kingdom, following "Welcome to the Black Parade" and "Famous Last Words", both of which were successful hits for the band. The band opted to release "Teenagers" as the third single in the U.S. instead of "I Don't Love You". The band released the single in Canada, on MuchMusic on March 19.

While the band was touring, they began to record using the bus's recording unit. "I Don't Love You" was one of the only songs to be used on the second-to-last album from the tour bus jam sessions. Ray Toro and Gerard Way can be seen playing an early version of the song from the tour bus sessions on the 2006 DVD Life on the Murder Scene at about 1:57:13 on the first disc.

The music video was directed by Marc Webb who also directed three previous My Chemical Romance music videos, from their Three Cheers for Sweet Revenge album. Webb was chosen instead of Sam Bayer who directed "Welcome to the Black Parade" and "Famous Last Words" from their third studio album The Black Parade. The music video is about two lovers, played by Colton Haynes and Cassandra Church, in a strange abstract world, and the video seems to tell the story of how their love quickly withers away until one leaves the other alone. Towards the end of the video, one of the band's amplifiers explodes along with two of the guitars. On March 7, 2007, the band exclusively premiered the video on their YouTube channel, and on their MySpace. The video is in a black and white format, most likely to simulate more contrast between the two lovers. The music video also shows Gerard with his newly dyed black hair, which he has sported since late December. There were also reports by one observers of Gerard wearing a wedding band (as can be seen in the video), which Gerard was asked about in an interview with 97X, where he mentioned that he had 'found someone very special' . The video appeared on Kerrang! TV in the UK on March 9, 2007, and on Channel 4 in the UK on March 8, 2007. The clip also shows the band members falling but not landing, in the order of Mikey Way, Ray Toro, Bob Bryar, Frank Iero, Gerard Way. The video was made available on March 19, 2007 for purchase on the UK iTunes Store. The video was released in New Zealand on March 13, 2007.

...
Wikipedia