There's Something About Mary (1998)

Ted's (Ben Stiller) dream prom date with Mary (Cameron Diaz) never happens due to an embarrassing injury at her home. Years later, Ted hires Pat Healy (Matt Dillon) to track down Mary so he can reconnect with her. Pat lies to Ted about Mary and he finds out everything he can about her to trick her into dating him. Ted travels to meet Mary and has to weave through the web of lies that Pat and Mary's friend Tucker (Lee Evans) have woven to try and win her over.