If your dh had been shagging around for 30 years would you want to know?

[gotthearse]

Long tale that I won't recount in full for fear of exposure. DH has found out FIL is a serial cheat, in a really big way. He's devastated - FIL has always been his hero, and now he has no idea who he is. DH feels very strongly that he wont lie/cover up etc but can't bear to break MILs heart. It's all such a mess, and he's stressing about the devastation that will ensue, or that MIL will hate him for exposing the whole sorry mess. Likely that MIL has no clue, FIL's job gives him a lot of opportunity to get away with it.

I'm two years off 60. From recent experience I'd say that the worst thing someone you love can do to you is deceive you. I would want to know and to be in charge of my own way of dealing with it. I would take a dim view of anyone deciding they knew better, no matter how much they thought they had my interests at heart.

I would tread carefully. My parents are in an unusual situation in that they're separated and my Dad lives with another woman who he had a longstanding affair with. But they still spend a lot of time together with their children and grandchildren. This situation has been going on a long time.

My Mum has never moved on and while in a way I wished she had starting over is really hard. The breakup of their relationship shattered her confidence and it has taken years to rebuild it. The main problem my Mum has these days is just general loneliness. She misses the companionship she shared with my Dad and the common history.

I suppose what I'm saying OP is that your DH and BIL may want to talk about this to their Mum but they need to support her. That may be her choosing to stay with unfaithful FIL. They need to be led by her in their dealings with FIL. His being unfaithful could actually be less important to her than a schism in the family between her sons and their Dad.

I know someone who has done this. His wife has been doing the same. Pathetic, selfish behaviour.