TV tonight: 'Big Bang,' 'Glee,' 'Parks'

• Sheldon has to play nursemaid on 'Big Bang Theory'
• What happens after sectionals on 'Glee'?
• Megan Mullally returns on 'Parks and Recreation'

Big Bang Theory
CBS, 8 ET/PT

Some of the best-loved Big Bang moments feature a sick Sheldon demanding care — which for Sheldon always involves a rendition of his favorite song, Soft Kitty. Tonight though, the shoe's on the other foot, as Sheldon plays nursemaid to Amy. Odds are a few rounds of Soft Kitty are not going to be enough.

Glee
Fox, 9 ET/PT

We pick up from last week's sectionals collapse by Marley, a plot point so heavily telegraphed, the poor child should have been wearing a "Watch me pass out" sign around her neck. It would be nice if Kitty — who encouraged Marley's plunge into bulimia and an addiction to laxatives — were forced to face some real-world consequences, just as it would be nice if the show did not use this sectionals performance to put the club's existence in jeopardy yet again. (No small Ohio town is going to let go of a club that just brought it a national championship.) Still, eating disorders are a serious problem for teenage girls, and Glee is one of the few shows that can address that issue and that audience. So let's hope the heavy-handed start is not an indicator of where the story is headed.

Parks and Recreation
NBC, 9:30 ET/PT

Megan Mullally, who is married to star Nick Offerman (Ron) in real life, returns as Ron's ex-wife Tammy II, and just when things were looking up for Ron. He has been nominated for a woodworking award, and planned to celebrate at the awards dinner with Leslie and Diane (Lucy Lawless) as his guests.