'I have to tell my brother that his wife has been cheating for the last thirteen years.' UPDATED

"Tomorrow I have to tell my brother that his wife has been cheating for the last thirteen years. How would you handle this?"

My SIL confided in a mutual friend who has told me the details of multiple affairs. At this stage I have screenshots of their conversations as proof and am seriously considering paying a hacker to get into my SIL’s instagram to capture the chat logs, in case he needs the evidence.

Not that I even know how or where to find someone to do this. But I know she has these chats on her phone still. He could see them himself but I want the proof in case she tries to delete it.

This will absolutely destroy my brother. It’s not even a question of IF I should tell him.. I need to. I’m just seriously concerned about what it will do to his mental health. He’s been cheated on before and became severely depressed and suicidal. This was many years ago, and he’s a grown man now. I’m just still very concerned about it.

She admitted that she’s not attracted to him. She gloated to our mutual friend about the fact that he’d do anything for her. It’s all so vile and disgusting. I’m not sure why I’m even writing this here, I know what I need to do. I suppose I’m just looking for advice.

I haven’t told anyone about this yet. I don’t want this to be gossip shared behind his back if he decides to stay with her. I truly hope not but they’ve been together since they were both in high school and I think he will struggle to detach from her. Any advice would be greatly appreciated.

Relevant comments:

Commenter 1: I think to tell her you know and give her the chance to come clean with your brother. If she doesn’t then you tell him. You have the proof already so if she tries to “get rid of” anything, you already have the backup. I only say this because relationships are so complicated and you don’t want to get wrapped up in it.

Commenter 2: Cheaters lie and will paint op as a liar or minimize it as just flirting.

OP: Exactly! She’s quite manipulative and I just know she will try and cover her tracks. I want to make sure she’s caught off guard and doesn’t have a chance to delete anything. I also hate that I’m involved but I can’t cover for her

Commenter 3: Is there a way you can postpone it so you’re not completely blindsiding him 2 days before Christmas? I just feel like that’s a really terrible time to do it.

OP: Yeah the timing sucks. The reason I want to tell him now is because we’re due to attend a concert all together, a few days after Christmas. And I can’t bear to go with them and pretend. I think you’re right though, perhaps it’s better to wait a few more days

Commenter 4: I would suggest that you gather as much proof as needed to make it irrefutable. Then schedule a time with a counselor and ask him to come along for support. Let the therapist know of your plan to tell him in their presence to ensure they will be willing to be there to support your brother as an impartial outsider. This should be done carefully given his history.

OP: Thank you for that advice. I agree and I’m trying to gather as much information as I can so there’s no room for her to deny anything. I’ll definitely look into getting extra support from a therapist.

Two days later, she shared this update:

In my previous post I explained that I (32F) recently found out that my SIL (33) has been cheating on my brother for their entire relationship and marriage. I ended up telling our younger sister about this too because I couldn’t keep it to myself. We both decided that it’d be important for us both to be there when I tell him.

We decided we wouldn’t say anything negative about his wife, rather just stick to the facts that we knew. I told him to meet us at the park near our parent’s place and when he got there, I immediately burst into tears.

I told him that I found out something horrible that I had to share, that I was sorry to be the one to tell him this, especially at this time of year, and that his wife has been having multiple affairs over the course of their entire relationship.

I asked if he wanted to see the evidence that I had, and I apologised for showing him the vile messages. It absolutely broke my heart, but he started sobbing reading them. They were very explicit.

We spent a few hours talking, crying, and comforting him. We offered to go with him when he confronted her, not to interfere, but to be outside the house in case he needed support. They live in a rural area and I was worried about him driving and being alone. I also set up a spare room in my house for him to stay in.

I have to say that I am so damn proud of this man. He was calm and level headed. Told us not to worry, and that his mind and conscience were clear. I told him I was afraid to tell him because I knew how much it’d hurt him, and because of his past depression and how it’d damage his mental health.

My sister and I told him we love him and that he’s the kindest most loyal person and brother. He’s always looked after us, and looks after everyone. He thanked us for telling him and said everything would be okay. I made him promise that he would be careful, look after himself, and wouldn’t hurt himself or her. Later that night, I went to check on him, and he came out to talk and give me a hug.

He said his wife wasn’t holding back, and was coming clean about all of it. He said that after the torture he’s been putting his body through with training and boxing, this feels like nothing in comparison. He’s in shock of course and in a world of pain, but he’s so mentally strong. This is the most horrible thing I’ve ever had to do. And I feel so sad for him.

We said we’d support whichever decision he makes, and that we wouldn’t tell a soul about it if he chooses to stay with her and wants to keep it private. Thanks to everyone who commented and gave me advice. I desperately needed to talk about it.

Relevant comments:

Commenter 1: If he chooses to stay it would be detrimental to his health. She wasnt cheating one time or for a few months, but for the entire marriage!

OP: I truly hope he doesn’t stay. I can’t imagine that he will now that he knows how long it’s been going on for. I think if he does in the short term, it will ultimately end in divorce regardless.