<human>: Can you succinctly summarize the text in 1-3 sentences?

So, I've always had a slight idea that my father has cheated on my mom all my life. I never really realized how bad it was until I got older and I realized all the signs i missed and overlooked as a child. 

I remember times I would look for my dad around the house and he would be locked in his bedroom with my aunt and they'd be giggling...

I remember a time when I was in elementary school, and I had a (female) friend over and he separated us and locked himself in the room with her. Her family moved shortly after.

And worst of all my little cousin (not blood related, just a family friend) who trusts me more than anyone, admitted to me that my dad did something sexual to her, she told me when I was in middle school, I cried, but we both agreed that we could never tell anyone especially my mother.

I am sick and tired of keeping in these secrets, especially recently with my mother constantly being on my back for smoking weed which is really the only thing that helps me forget about these fucking disgusting problems.

It's tearing me apart I'm visiting home for the weekend from college and, my aunt is in the house right now, my dad is in the house right now, and my mom is trying to give me the 'marijuana talk' once again, and all I want to do is tell her she has a much more serious problem to handle and its right down stairs. 

I'm sorry if this post seems pointless as I'm not really asking a question. I just legitimately have no one to turn to. I want to tell my mom but I'm scared of what will happen as my dad is the only one working in my family and also pays for my college and I also have a 6 year old little brother.
<bot>: My Dad has cheated and done horrible things all my life, Mom has no clue and keeping in the secret is tearing me apart everytime I come home.