My bf and I are good friends with married couple. Problem is they tell us each stuff they don't want the other to know. Bf and i keep no secrets from each other and the husband has told me too. He is about to cheat. Should i send an anoumous letter to the wife to warn her to check his phone bill? Or just not say anything. I know in her situation i would want to know. I can not think of another way to do this without the husband who is a friend getting mad.