At a college party, best friends Roy and Kelly agree that if they were still single at 30, they would marry each other. As Kelly’s 30th birthday nears, she finds out that Roy is getting married. Can she accept this and let him go, or will she take decisive action, knowing she’s been in love with Roy all these years?

Ten years later, Kelly’s birthday approaches, and she is about to turn 30. She discovers Roy is engaged to Vanessa, a woman he met on a business trip. Roy asks Kelly to be Vanessa’s maid of honor, and she reluctantly agrees, hiding her true feelings. Kelly tries to sabotage the wedding but ultimately feels guilty and rectifies her actions.

On the wedding day, Kelly finds an old letter from Roy confessing his love for her from years ago. Realizing she can’t let him go, Kelly rushes to the wedding and interrupts the ceremony, revealing her feelings. Roy faces a difficult choice between his current fiancée and his long-time best friend.