I Love You Beth Cooper (2009)

Genre: Comedy
Runtime: 102 min
Country: Canada
Language: English
Tagline: Five Little Words Can Change Your Life
Starring: Hayden Panettiere and Paul Rust with Jack T. Carpenter.

Plot:
A nerdy valedictorian proclaims his love for the hottest and most popular girl in school – Beth Cooper – during his graduation speech. Much to his surprise, Beth shows up at his door that very night and decides to show him the best night of his life.

http://www.imdb.com/title/tt1032815/
http://en.wikipedia.org/wiki/I_Love_You,_Beth_Cooper_(film)