Call off the Wedding!

Sometimes when a heroines married the wrong guy or the main antagonist (who they never love or met each other), the main protagonist came in and yelled "I object!" which he'll admit that he always love the heroines or tell her that she shouldn't be with him since the main antagonist isn't her true love, etc.

Heck, that's why it's called True love or love triangle if you find someone special or make the heroes realize that you're in love with someone else by deciding to call off the wedding and decide to be with the main protagonist by confess their feelings for each other.

Sometimes, the main protagonist isn't ready or get nervous to be married yet, so he run away which it make the heroines hurt and confused,

Examples

 * Thumbelina refused to marry Mr. Mole, because she loves Prince Cornelius instead of him and Grundel the Toad.