Here’s the synopsis for the episode 2×16 – Clark Raving Mad of 90210. Do not read below if you don’t want spoilers!
NAOMI DECLARES WAR AGAINST A NEW FACULTY ADVISER AND CLAIMS SEXUAL HARASSMENT – Naomi (AnnaLynne McCord) immediately butts heads with the Blaze’s new faculty advisor, Mr. Cannon (guest star Hal Ozban, “Californication”), and is reprimanded in front of her peers. After failing to convince Navid (Michael Steger) to back her opinion, Naomi decides to tell a tiny lie that soon snowballs out of control. Adrianna (Jessica Lowndes) is now the lead singer of the Glorious Steinems and confides in Silver (Jessica Stroup) and Naomi about her newfound feelings for Gia, and the two go out on their first official date. Teddy (Trevor Donovan) decides to test Silver (Jessica Stroup) by attempting to make her jealous. Dixon (Tristan Wilds) and his birthmother Dana (guest star April Parker Jones, “Jericho”) continue to bond. Liam (Matt Lanter) catches his stepfather (guest star John Schneider, “Smallville”) with another woman and confronts him with his fist. Debbie (Lori Loughlin) and her instructor, Kai (guest star Greg Vaughan, “General Hospital”) share tea and conversation after yoga, but Kai oversteps his boundaries. Shenae Grimes also stars. Stuart Gillard directed the episode written by Tod Himmel (#216).
Source: The CW