Songfacts®:

• "Little Miss Obsessive" boasts guest vocals from Tom Higginson of the Plain White T's, who had a big hit in 2005 with "Hey There Delilah." Simpson wrote the song with Jim Beanz, Karl Berringer and Victor Valentine.
• The song was released as a single from Simpson's third album, Bittersweet World, in 2008. She told MTV News about the meaning behind it, which is relationship trouble: "It's a song that kind of relates to the last album, but it grew with the new record. And every girl has gone through that situation. You put your foot in your mouth and you go, 'Wait, why did I do that?' We're on our phones writing and texting too much!"
• Higginson was recruited for this song after hanging out with Simpson when the Plain White T's toured with her fiancée's band, Fall Out Boy. He told Rolling Stone: "After the tour ended, I got a text from Pete [Wentz] that said 'Ashlee wants you to sing on her album.' I was like 'Hell yeah, man' and I tried to bribe him by asking if he could have Brendon [Urie, of Panic at the Disco] sing on our next record because I'm a huge Panic fan."
  
  Simpson and Wentz got married in 2008 but divorced in 2011.