Should they? Deadpool was a very adult oriented film, with some advanced sexual content and graphic violence... I think it's R rating was earned. Deadpool 2 had the same graphic violence and milder sexual content.

Who in their right bloody mind would let their young kids watch a 15 rated film?

Who thought they couldn’t? I saw Freddy’s dead in 1992 with my uncle when I was 9. Was there some confusion about how R-rated movies work?

What are they gonna do, stop me?

@Anthony Stoner I'm the complete opposite... My parents always forbid me to watch anything with too much gore or swearing when I was young. Not that I'm not allowed to watch them now...