'You Selfish Little Brat!' Britney Spears UNLEASHES On Jamie Lynn Again Over Diva Behavior During Justin Timberlake Breakup -- And Even Invokes Xtina!

Daaaaamn! This may be the most Britney Spears has said yet about why she’s so angry with her little sister! In the wake of Jamie Lynn Spears‘ memoir hitting bookstores, Britney has been taking to social media to blast her kid sis with what she considers the truth about their relationship. Related: Rachel Zegler Apologizes For Dramatic Reading