My dad is cheating on my mum what do I do?
you really should talk to your father.
I know everybody is telling you not to tell your mother but I have to say that if one of my kids knew that my husband was cheating on me and didn't tell me I would be pissed off at them.
Your mother deserves to know, but she should hear it from your father. Talk to him and encourage him to tell her.
she'll find out and deal with it. leave it alone, he's an a$$ if he is, and besides...unless you actually SAW him doing it with another chick...it's likely that it might not be what you think. trust me, just mind your business. I know it sucks and it hurts, but just let it be. things will sort them selves out.
They are adults, let them deal with it between themselves. There's really nothing you can do.
ask a pastor for advice. or older people. or you should talk to your fahter
BUT MY DONT NO!!!