What movie is this

I have a question, I saw a movie in 2008 and it involved a guy who could view lady parts like the terminator and he suffered from sex addiction I think, in one scene the guy is in a restaurant and sees a lady going to the restroom, he follows her there and offers her money for a quickie, the closing scene is of the guy going to his girlfriend, who is a teacher, to apologize and she tells him to sit down in the classroom. Can anyone tell me the name of this movie?