Look Who's Talking Now was Britney's responce to Justin
Quote:
“She said nobody really listens to her,” Bell said. “She just wanted somebody to say I believe in you beyond this pop machine.” Bell developed a good relationship with Spears and the pair worked on a number of songs together. “After a while, she sort of trusted me,” she said. One song they wrote during the 2002 sessions, titled “Look Who’s Talking,” was about Timberlake but contained references in its lyrics only he and Spears would understand.
“That song was totally about him,” Bell said. “It was all, let’s not put it all out there. She was like, ‘He’ll know what we mean, but the rest of the world won’t.’” In one line, Bell remembered, Spears used the word “justify” for its double meaning (Timberlake’s album was titled Justified). “I was true to you / Justify my point of view,” she sang. The song was covered by Korean singer BoA in 2008, and Spears’ version leaked in 2012.
Probably Base. For future reference! 
