My brother's lady is an absolute sweetheart. They've been together about a year. She is stunningly beautiful, kind, caring, cooks for him all the time and has taken on his son as her own - but she does have issues with low self esteem.
As for my brother, he is a good guy deep down, intelligent and creative, girls go crazy for him but he has always been a bit of a player. He acts quite emotionally abusive towards her (and all women) and I have told her before not to put up with this but she is so understanding she believes it's his issues causing it, so is forgiving. However I don't see her super often as I don't see him much.
Last time I saw him he was ranting about how he has dated better looking girls than her (she is early thirties, naturally pretty, he usually dates younger girls who are fake tanned/caked in make up) and he seemed really concerned that his friends weren't so impressed with her as they were with his exes. I told him where to get off with that attitude and said he should be grateful, she is the best woman any man could wish for. Inside and out.
However have just found out that not only has he been dating around behind her back, but also he has now cheated on her. She is serious about him and goes out of her way to please him - plus she is at an age where she is thinking about having kids.
I am completely torn, on one hand it isn't my place to tell her, I only see them about once a month and she would likely just stay with him regardless and talk it through as she adores him. But as a fellow woman I feel she has a right to know he has not been loyal to her, and possibly is even putting her health at risk.
What the hell do I do? Speak to my brother and tell him if he doesn't come clean or seriously change his behaviour, I will alert her? Or just stay out of the whole thing? Never been in this position and I feel sick.