Songfacts®:

• The three-and-a-half minute track was co-written with British-Tamil singer-songwriter Mathangi Arulpragasam, better known as M.I.A. In the song, Aguilera compares her love to office supplies: "If I was a ruler I would set you straight/but your love is like a sharpener/ it really grates." M.I.A. also takes the microphone for more stationery analogies.
• This is one of several collaborations on Bionic after Aguilera's then-husband, music executive Jordan Bratman, suggested she contact some of her favorite musicians and ask them to appear on the record. Aguilera assembled the album by contacting her partners directly. "I said, 'I'm a really big fan of yours, and I'm interested in stepping into your world and what you do,'" Aguilera told Billboard magazine. "'I want to combine that with my sound, and let's see what happens.' I feel like I can do so much with my voice. I would be so bored sitting on a stool singing ballad after ballad just because I can."
• M.I.A. told MTV News that she was looking forward to hearing the pop star belt out her trademark high notes for the song and was surprised when Aguilera decided against it. The British-Sri Lankan singer said: "Other people were involved who I respect like Peaches and it was like a sea of women coming together to write this new thing. Christina had also had a baby, you know, so it was kind of an interesting situation.
  I really thought I was going to be able to go in there and get her vocals on to the next level and she didn't want to do it. She was like, 'You might think that's great because it's not what you do, but to me I'm really bored of it.' It's interesting getting to work with people who can do things vocally that you can't."