Aarti Mann having a blast on 'Big Bang Theory'

Every TV show needs an antagonist, and this season on CBS’ “The Big Bang Theory” (8 p.m. EDT Thursday), that role belongs to Aarti Mann. She plays Priya, the sister of Raj (Kunal Nayyar), who has become the girlfriend of Leonard (Johnny Galecki), much to the dismay of Leonard’s ex-girlfriend, Penny (Kaley Cuoco). In the final two episodes of the season, Priya will play a central role, especially in the season finale.

“Basically, things between Penny and Priya come to a head,” Mann said in a phone interview earlier this month from the Los Angeles home she shares with her husband, who works in finance. “Priya has to face the music, and she and Leonard come to an important crossroads.”