Help idk what to do about my mom cheating on my dad

I(16M ) found out my mom(41F) was cheating on my dad (40 M) since at least January. I knew that she was xheating since she would have the yellow glow of the phone when snapchat op3ns and ive seen her on it and on insta although claiming she bever had those. Well last month i fpunf her login ibfor on a postit note and loghed on to see she is talking with a man and someone about 20 still in school. I know if i confront uer with the proof she will deny it and get mad at me forfinding out. And i cant tell my dad because i dont want him to end up in the hospital again.I have no one i can tell or look for advise so i am looking on here. I once mumbled about it to my mom and she got all mad and defensive that shes not talking to no one. I know is worng that i am looking a the chats but shes told the guy that shes hidden money so she can run away with him and that hes gonna come pick her up soon. ( sorry if word are mispelt had to type it before my dad sees) UPDATE: i think my dad knows... he told me that hes gonna start putting money aside because nothing is making sense cash wise. That it doesn't make sense on how cash is disappearing and he was gonna say something else but he didnt. UPDATE: i went to see if she ever talked to him today and she did but he never replied . And i check again right now and i though oh shit! She changed her password. Idk what to do know.