MONDAY, DECEMBER 10

"90210" - (8:00-9:00 p.m. ET)

"The Things We Do for Love" (TV-14, D) (HDTV)

MUSICAL GUESTS TEGAN & SARA PERFORM AT THE FRIENDS' HOLIDAY PARTY - When Alex (guest-star Trai Byers) approaches Max (Josh Zuckerman) about forming a new company with him, Naomi (AnnaLynne McCord) intervenes by attempting to persuade Bryce (guest-star Amber Stevens) to rehire Max at his company. Naomi convinces Navid (Michael Steger) to take Bryce out for drinks, and after a few cocktails Navid uncovers the truth about Max's termination, which leaves Naomi pondering the fate of her marriage. Then, Liam (Matt Lanter) receives a blackmail letter about Vanessa's (guest-star Arielle Kebbel) accident, and Annie (Shenae Grimes) agrees to lend him the money to help trap his blackmailer. But when Adrianna (Jessica Lowndes) tells Ashley (guest-star Natalie Morales) that she spotted Vanessa at the beauty salon, Ashley wrongly suspects that Liam was headed for a secret rendezvous with Vanessa. Meanwhile, Silver (Jessica Stroup) is distraught when Teddy (Trevor Donovan) refuses to sign over his parental rights and tries to convince her to let him co-parent the baby. Matthew Diamond directed the episode written by Marjorie David (#509).