I suspect that my dad is cheating on my mom, what should I do?

I am 16 years old, turning 17 in exactly 4 months, and I went onto my dads computer today to learn how to make something in blender for a youtube thumbnail. I was trying to find steam and I went to “desktop 2” and there I saw, tucked away half off the screen on the right, a file. Only half of the words were visible. I saw, “Chat…” on the file, so I pulled it out so I could read it fully and it read, “Chat to women online…”.

It was a google Chrome link saved on the desktop. Curiosity got the better of me and I opened it and it brought me to a search result page with a bunch of dating sites. I tried to open one of them but they wouldn’t load for some reason.

I went back to the desktop to see more information about the file, and it told me when it was created, so I went onto google and went to his search history and scrolled down to the date the file was created. I saw a bunch of links to searches for escort ads, erotic/ sensual massages, dating sites, “sexology”, etc.

I deleted my search history so that he wouldn’t know I was snooping, and closed out the file, and went back to desktop 1 and left everything where I found it. I put the mac book back where I found it and went on a walk.

After I got back, I went on his laptop and clicked the escort ad to see if he had made an account but I couldn’t tell whether or not he had made one.

This isn’t the first time I’ve had suspicions. When I was about 8 or 9, I was on my dads phone and I saw a dating app on his phone. When I told him he acted like he didn’t know how and why it was there, and deleted it.

I was planning on investigating further to find proof that he was/ is cheating, but I ultimately decided against that because if that kind of news came out, it would rip our family apart, and I didn’t want to be the one to keep information that had the potential to rip my family apart a secret, or be the one to share it and be caught in the crossfire. Without my dad, my siblings would be heartbroken, my mom would be heartbroken, our living situation and/ or financial situation would change very fast. There are more cons than pros, it’s a lose-lose in my opinion.

I would feel extremely guilty if I kept it a secret, especially if I didn’t tell my mom, but I don’t want the family to be ripped apart and completely screwed in every aspect. And I can’t confront my dad about it because he is very manipulative and emotionally immature and me confronting him would probably backfire on me.

Should I tell my mom or not? If so, how do I tell her? Should I show her what I saw on the computer?