"Just don't." - Mark Kermode, BBC Radio 5live
A really genuinely horrible film that made Mark want to have a shower after watching it. All the worse for having actors of the level of Robert De Niro and Zac Efron in it. In fact this was the film that ended Mark and Zac's special thing.
A film that cannot be unseen, no matter how much you wish it could be. So bad, it forever spoiled Mark's memories of Robert de Niro's phenomenal body of work, to the extent that watching The King Of Comedy meant that rather than see Rupert Pupkin being brilliant, he would picture Zac Efron walking in on him and finding him relaxing in a gentleman's way. Everyone involved should be thoroughly ashamed.
It is down there with Entourage in its relative merits, and in that film has its potential match as Hellish double bill. It also reminded Mark of Movie 43 - in that it made him wonder what the director had on the film's stars that could in any way have persuaded them to appear in it.
Dirty Grandpa should not be confused with Bad Grandpa, which was a Johnny Knoxville film that Mark didn't like much, but didn't actively detest in the way he hated Dirty Grandpa. Nevertheless, Dirty Grandpa frequently finds itself being referred to as Bad Grandpa.
It has come to something when confusing a Johnny Knoxville vehicle with a Robert de Niro movie is besmirching to Knoxville.