When Brittany and the gang try to convince Mr. Schuester to let them do a Britney Spears number, he is reluctant to go that edgy. Meanwhile, an insecure Will is curious about Emma's new beau, Dr. Carl Howell, so he convinces her to bring him in to talk to the kids about dental hygiene. While the dreamy doc inspires the girls to take their dental health more seriously, Will is left feeling worse than before.

The glee club works on a duet assignment, and Finn and Rachel plan to throw the competition so that Sam can have a shot at winning. Meanwhile, a love triangle between Mike, Tina and Artie develops.