My girl's Mom is a cheater. Her parents were separated after the first time she did it, but they've been together for years now and are mature in age. She's cheating with a co-worker and her dad has no idea and no one else knows. They both drink heavily and she calls him after her dad is passed out and will see him on weekends later when he's asleep after drinking etc. They BOTH drink, that's not the issue. Her co-worker is married himself, younger, kids, etc. No one else knows. If we tell her we know, she won't care. She has no respect and no conscious. What to do? #1 - Tell her father what's going on. (he may do nothing, drink more, leave, who knows) As smaller town, if he is told, everyone will find out including the guy's wife and may destroy their family. #2 - Mail anoynomous letter to man at his work saying someone knows and will tell your wife if it doesn't stop. (problem here is her mom may just then go find another guy and doesn't solve our problem) #3 - Do nothing, she'll go to hell and so will the other guy, let everything be. Better no one finds out. lol ......other options Any advice? I always find everyone on the board to have great comments and insight on life experiences. What would you guys do????