Fever Pitch(2005)

When Ben Wrightman, a young teacher, begins dating pretty businesswoman Lindsey Meeks, the two don't seem to have a lot of the same interests, but they fall in love, regardless. Their romance goes well until baseball season begins, and Lindsey soon realizes that Ben is completely obsessed with the Boston Red Sox. Though she tries to understand Ben's passionate team loyalty, eventually it threatens to end their otherwise happy relationship.