Why did you have to tell me THIS now?

I'll be honest. I love watching romantic comedies. From My Best Friend's Wedding to the Wedding Planner, a common device used is the revelation of romantic feelings for someone at the very wrong time, like right before they're about to marry someone else.

And just when I thought it could only happen in the movies, I began hearing stories from friends and family members of being on the other end of this expression. Usually, the stories came after someone became engaged and someone stated in some form or fashion "I thought I was going to be the one to marry you."

From there, the conversations went downhill. One person actually responded "well if you had told me this two years ago before I began to think of you as my sister, it could've been different." More or less, they all responded in some way that said the timing was inappropriate.

While I'm all for expressing how you feel, after someone has gotten engaged and right before they get married is the wrong time to do it. More than likely, the person is already going through a lot of convoluted emotions as they are about to take a major step in their life. Revealing that you have been in love with them for the last five years is not going to help and only going to confuse them more.

Has someone close to you ever expressed feelings for you when you were heavily involved in another relationship? How did you react? How did it affect your relationship with that person?