[TL;DR] I've found out my Mum is having an affair with a close family friend. I want to confront her or tell my Dad but we're all in stuck in lockdown together. Need advice on how to proceed
Quick background: I'm the eldest of three siblings, my sister and I are living at home for lockdown, my parents are married and grandmother lives with us.
I first found out about my Mum's affair at Christmas. I was helping her sort some problem with her phone, she had left the room and I pressed the wrong icon on her home screen and it opened up to her text messages. I went to close the app but paused, it had opened to a conversation with someone who's name had been saved as only a string of four seemingly random capital letters. This was odd enough to catch my attention, so I skimmed the conversation. It wasn't anything especially incriminating, but the language seemed strangely intimate and there were a lot of x's at the end of each message. My mind immediately jumped to the idea that my mum was potentially having an affair. I was so stunned that I couldn't think to do anything other than just closed the app, and when Mum came back I just acted normal and made the excuse that I couldn't fix her phone problem.
I spent the rest of the holidays trying not to think to much about it, and hoped that I had misread or misinterpreted what I had read. It was a relief when the holidays ended and I got on the train to go back to the town I'm was working and living in.
Fast forward to March, lockdown has just started and the contract on my job has ended so I move back in with my parents, rather than be stuck by myself. Over the last few months I had occasionally thought about what happened over Christmas and decided that I had to find out one way or the other if my suspicions were right. I got lucky, or unlucky depending on how you think about it, a week or so in to lockdown when my Mum and I were in the kitchen. She had just been on her phone, put it down on the counter without locking it and then walked out the room. At the time I didn't know the code to her phone, so this was as good as a chance I was going to get. I opened her texts and found the conversation I was looking for, and it confirmed all my worst suspicions. There was text after text about how much they missed each other, how much they were thinking about each other etc etc.
Knowing that she was definitely guilty I decided I needed to get evidence. I didn't want to be in a situation where she could deny what she has been doing when my Dad finds out. A few weeks ago I saw her put in part of the code for her phone, I later tried to unlock it and after a few tries got in.
Since then I have taken pictures of the conversations between between my mum and her lover. The texts have been pretty incriminating, including a couple of blessedly short sexts that were incredibly uncomfortable to read. I've also answered the important question of who the man is. While reading through her texts I saw one asking him if her would help her with a zoom quiz she was hosting, scrolling down I saw she said she had emailed him the questions. A quick flick through her emails and I got a name. I really couldn't believe it when I read it, he's a close family friend. I've known him most of my life, he's my brothers godfather, before this I liked and respected him, he's one of my Dad's few close friends. He's also married, he's got kids and grandkids.
The worst part about all of this is that I'm not even that surprised. My parents are not a good match, I've often wondered why they got married. They don't have very much in common and don't really find any joy in each others company. Whatever love that had for each other has dried up. They used to argue a lot but they don't anymore. I think they have just resigned themselves to this situation, one that is familiar and relatively comfortable for them. I think I can even understand why my Mum, feeling trapped in a loveless marriage, would have an affair and seek out the the pieces of her life that she feels are missing from her marriage.
What's has stopped me from saying anything is that the ramifications of this scare the shit out of me, we are a relatively stable and happy family and this would tear us apart. And there's my Dad, he doesn't deserve to go through this. I'm terrified of how he'll handle it, that it will break him. He doesn't have much of a support network, doesn't hangout with friends casually, he used to play a lot of sports and socialise there, but as he's got older he done it less and less. I'll feel responsible because none of this will happen unless I tell him about Mum's affair.
So this is where I need advice, I have been racking my brain about how to proceed and haven't got a good answer. Do I tell my Dad first or do I confront my Mum? Do I talk to my sister who has often been someone I can confide in and get her to help me, but also burden her with the knowledge? Do I do it now, or wait for lockdown to be over?
I haven't spoken about this to anyone so I really appreciate all of you that have read this. Thanks