The point has been made already, but it bears repeating.
When an abused person confronts the abuser, whether it's in person, in a letter, on the phone or whatever, the confrontation is for the benefit of the abused person, not the abuser.
I took the letter approach, because - well - I'm a writer. And a letter gives you time and space to think about what you've said and to add to it, to subtract from it, to wait a while and make sure you haven't left anything out.
And you can always threatent to multiply copies of it and send it to a million people if the abuser doesn't respond. Worked for me.
Good luck,
Francois
Where it is a duty to worship the Sun you can be sure that a study of the laws of heat is a crime.