Love life can never be always a smooth sailing one and you tend to make mistakes. It is never too late for a sweet sorry to your beloved and a sorry card makes your work easier and faster. To err is human, and to say a sorry is chivalry.
If you really love the person and want him/her to remain with you forever, a sorry becomes a small word patching up huge mistakes. Choose a sweet little baby face crying for the mistake or a little bear bending on knees to beg the pardon, and see how the angry red face of your sweetheart turns pink with blush.