Believing the glee club members are becoming complacent ahead of the forthcoming sectionals , director Will Schuester ( Matthew Morrison ) divide the club into boys against girls for a mash @-@ up competition . Cheerleading coach Sue Sylvester ( Jane Lynch ) observe that head cheerleader Quinn Fabray 's ( Dianna Agron ) performance standards are slipping . When Quinn blame her tiredness on her glee club participation , Sue renew her resolve to destroy the club , planning to sabotage Will 's personal life .