As the very public feud between Jamie Lynn Spears and Britney Spears heats up, it appears the “Toxic” singer’s ex Justin Timberlake wants no part of it. In case you missed it, Jamie Lynn wrote about the Justin and Britney’s 2002 breakup in her new book, Things I Should Have Said, saying she was “deeply affected” by the split. Then Britney, 40, posted on social media that she should have “slapped” Jamie Lynn, 30, soon after the Justin breakup for being “selfish.” So, where does all this leave the “Can’t Stop the Feeling!” singer?