S02E20: The Graduate

Alex is so sure that he will be named valedictorian of his class that he can't cope with the thought of being defeated by a girl especially his girl so his budding romance with Rachel is threatened when she wins the honor. The dismayed and shattered Alex, who even memorized his valedictory speech, feels cheated out of an honor he felt was his destiny all thru high school and he precedes to sabotage his relationship with Rachel.