Grossed out by dads computer. What do I do?

I'm not an IT specialist or anything but I know a thing or two about using computers. My dad does not. He uses one but he always calls me for help. Lately he's been having a very hard time remembering his passwords. I explained to him that in Mozilla Firefox you can store passwords. He said okay thats good but he couldnt remember them in the first place and just wanted a paper list. After much arguing I took it upon myself to hop on his computer and just write down all the passwords for him in a list. I was disgusted. His passowrd for EVERYTHING, which was stored in Firefox so it was easy to recall, was 'JohnnysGayTits'. My name is Johnny. Nobody else we know is named johnny. I haven't spoken to him about this and I dont know what to do. What should I do?