Quite possibly, this is the cruelest thing that you could do to someone. Particularly when you don't understand it or only know part of the truth (at best), anyway. Let people live; let people learn. (Those are not my words but well said.
In this day & age, blood does not make you family! The people that share your blood, are usually the ones to hurt you the most! I have my family that are full with the people that I became friends first!
People with good intentions make promises. But people with good character keep them. Keep your promises, and I promise to keep my good character. Do we understand the logic here. A promise is a promise :-) *m