In the latest episode of "90210": Once again, we begin where we'd left off the previous episode, with Annie and Naomi staring, stunned, at Sean. The girls introduce themselves as his half-sisters, and recoil when he implies that the two of THEM are sisters.
Sean's arrival does nothing to derail the enmity between Annie and Naomi. Annie spends half the episode seething, making nasty remarks about Naomi's footwear, and confronting Naomi in melodramatically dorky fashion; Ethan and Silver think it's funny at first, but eventually it starts to wear on Ethan, who asks Annie what's happening to her. She wonders that herself, asking Silver if she's changed since she first moved to Bev Niner -- she didn't used to be mean, or care about clothes, and she doesn't want to turn into the very Naomi she hates. Silver points out that she doesn't have to.