What to Watch: Tuesday, April 13

Calling all gleeks! Glee's misfits are back for even more chart-topping a cappella! Meanwhile, jealousy rears its ugly head for 90210's sexiest couple, Adrianna and Gia and Adam Lambert returns to American Idol before performing this Saturday at the GLAAD Media Awards in LA!Tuesday, April 13 8:00 pm Dancing with the Stars, ABC (1 hr) NEW Who will be the pair to go this week? Will it be rhythm-less hot momma Kate Gosselin? Keep your fingers crossed that sassy gal Niecy Nash and gay partner Louis Von Amstel stay dancing!

Adam Lambert mentors on tonight's American Idol!

8:00 pm American Idol, Fox (1 hr) NEW Don’t miss as last season’s runner up and GLAAD Media Award performer Adam Lambert lands a guest spot on tonight’s show as a mentor! 8:00 pm 90210, The CW (1 hr) NEW Gia and Lila get jealous of Adrianna’s and Navid’s friendship, while Naomi testifies at her sexual-harassment hearing. Also, Dixon and Ivy’s pseudo-relationship leads to something unexpected. 9:00 pm Melrose Place, The CW (1 hr) SEASON FINALE Amanda gives bisexual Ella the boot, but she will not go down easily! Meanwhile, Jonah and Riley try to make amends, and Dan and Lauren get back together. 9:30 pm Glee, Fox (1 hr) MID-SEASON PREMIERE It’s back with even more pizzazz! The glee kids, including gay member Kurt, work out new songs for Regionals, but hit some snags along the way. Also, Will enjoys the single life, but will Emma share his excitement? 10:00 pm The Big Gay Sketch Show, Logo (30 min) SEASON PREMIERE Don’t miss the big premiere, where out actress Rosie O’Donnell makes a guest appearance and the cast spoofs everything from the Amazing Race to Barbara Walters interviews.