There's Something About Mary Overview

Ted (Ben Stiller), now in his thirties, had a disastrous first date with his longtime high school crush, Mary (Cameron Diaz). Years later, he realizes he's still in love with her and decides to find her, in hopes of rekindling their long-ago romance.

He hires a private detective named Healy (Matt Dillon) to find her. The only problem is, Healy falls head-over-heels in love with her himself. So he reports back to his client that she's a 250 pound behemoth living on welfare with her four fatherless children. Ted checks it out and realizes Healy is lying, but in the meantime, Healy has scored some dates with Mary. Now Ted has to win her away from him.