Long story short...I am a teacher, a close friend of mine is in a relationship with the Father of one of the girls who is in my class. He was in a 24 year abusive marriage with the girls mother. He has convictions for domestic violence, abused her for many years and has recently lost his job for abusing alcohol and cocaine. She met him through the boyfriend of her sister who is also a nasty piece of work. I only know his background because I taught his daughter. I cannot reveal to my friend all of what I know about her new man or I may compromise my job. I am wondering if I should gently let a mutual friend of ours know some of his background so she and I can keep a eye on this relationship. I am so worried for my friend but am at pains to know what to do for the best..any advice very welcome!x