I was on my dads phone earlier and he got a text from a girl so I started reading these messages and I found out that he has met this women behind his girlfriends back so I went down his messages and saw that there was more than just this woman there was like six different women he has been seeing behind her back and I really don't know what to do , I have to do something... they are engaged and she is possibly pregnant... Help

No you don't do anything. It is his life not yours. Why were you snooping. Mind your own business.

You need to mind your own business. How would you like it if your dad went through your phone.
This is not your concern.

You do nothing, just let it go.

Mind your own business and stop snooping through other peoples phones.