I watched Bad Grandpa last Saturday.. and I don't know what i have to say about this movie...haha 

It was my first watching a Jackass and I though that this movie was really really weird but funny. I don't remember the grandfather's name, but his grandson is a billy who is 8 years old. When I watching this movie, I though 'how can the grandpa runs so fast?!.'

Yes. His a fake grandpa. They takes this movie in audience along with hidden camera.  This movie is good for killing time!