Caught My Mom Texting My Ex

honestly I just need advice on a situation? I was checking something on my mom's phone, albeit without permission. I went to close the app and her messages were up next. I caught a glimpse and saw my ex's name. she has been texting my ex consistently for the past few months. we have been separated for about 3 years, after a 5 year relationship together. I have since moved on, and to my knowledge, he has become an alcoholic. I was overcome with questions immediately, so I had to peek. all I saw was that they had spoken about the two of them and my stepfather getting together. I knew nothing of this. I am so conflicted. I have so many questions, I'm not sure where to start. I just need help moving forward.