Everybody knows what a hate-crime is but what would be the definition of a love-crime?

The term already exists, although in legal documents it is usually referred to by the French term: "crime passionnel"

There is no such thing as a "hate crime." No one actually takes the time to measure someone's hate. Even if you could, it would be so unwieldy and inconsistent as to be meaningless.

No such thing.

Let me begin my answer with an example. Someone who sheltered and protected Jews facing deportation to the death camps in Nazi Germany would effectively be committing a "love crime" relative to the laws of Nazi Germany.

So let's take Wikipedia's definition of a "hate crime" and invert it to figure out how to define a "love crime." "A hate crime is a prejudice-motivated crime, which occurs when a perpetrator targets a victim because of his or her membership (or perceived membership) in a certain social group." So I would argue that a love crime is an illegal act of resistance against a legally sanctioned prejudice towards a certain group, which occurs when a perpetrator protects, shields or defends a victim against officially legislated discrimination or persecution for being a member of that group.

When committing a love crime becomes necessary to protect the innocent, there is a vast disparity between what is ethically just and what is legal or illegal according to the laws of a particular nation at that point in its history.

Stalking I suppose, but that's not really about love, but about delusion.

Real love won't hurt or scare the person they love

abortion?

that's

sex crime