'Big Bang Theory': 'Bent' Star Will Cause a Tension Between Leonard and Penny

Photo credit: Apega/WENN

A new girl will come in between Leonard and Penny when "The Big Bang Theory" returns with its third season. Co-creator Bill Prady confirmed on the red carpet of the September 15 Creative Emmy Awards that Margo Harshman was booked to appear as Leonard's new romantic interest.

The 26-year-old actress, who is best known for playing Tawny Dean on Disney Channel's series "Even Stevens", will portray Sheldon's new assistant Alex. She quickly hits it off with Leonard and this "may create a little tension" for the experimental physicist and Penny, executive producer Steve Molaro told TVLine.

Harshman has had numerous guest-starring experiences, including an episode of "Grey's Anatomy", "Modern Family" and "House M.D." each. She had a regular role on NBC's comedy "Bent", but the show lasted for only six episodes.

"Big Bang" itself will kick off the new season Thursday, September 27 at 8 P.M on CBS. A problem is also looming in Sheldon and Amy's relationship as Amy is "trying to drag Sheldon along further into this relationship," but Sheldon is "reluctant every step of the way."