(15M) think my mom might be cheating on my dad and I genuinely don't know what to do?

TL;DR: I'm 15 and I've noticed multiple things over the last few months that make me think my mom might be emotionally involved with another man. I don't know if I'm overthinking or if something is actually going on. I'm scared my family could fall apart.

I'm 15 and honestly I don't know who else to talk to about this.

A while ago I noticed my mom talking to a guy on Messenger. She had blocked him before but recently she unblocked him just to ask how he was doing. She even told him she would block him again after that.

Then the conversation kept going.

The guy started saying he loved her and wanted her love. He even started saying weird things about my dad. My mom replied instead of immediately ending the conversation and later I noticed what looked like her trying to call him back. After that he kept calling her too.

This isn't the first thing that's made me suspicious either.

A few months ago I saw my mom chatting with our neighbor on WhatsApp even though they normally never text each other. The next day those chats were gone. Then it happened again and again. Every time I happened to see that chat it would disappear later. I even remember seeing a message that just said "sorry" after older messages had been deleted.

Then one day I walked out of my room and saw my mom and that neighbor standing really close to each other. The moment they noticed me he left quickly and my mom suddenly looked nervous. She even offered me her phone out of nowhere which honestly made me feel even more suspicious.

Maybe each of these things has an explanation on its own but together they've been eating me alive.

The worst part is my dad. As far as I know he has absolutely no idea. I looked at him today and almost started crying because I felt so bad for him.

I don't want my family to fall apart but I also don't know what I'm supposed to do if my suspicions are actually true.

Has anyone been through something similar or have any advice for someone my age