Oh my goodness. No one should ever show this to kids, or teens for that matter... It's a good movie for adults though, adults absolutely being the key word.
I can see how this could be very confusing for young adults who are not sexually aware due to the rape/ fetish scenes. Wouldn't even watch this with a young person in earshot to be honest due to the sexual violence.
Your kids don't need to be sheltered from everything.
While I understand that it is a parental instinct to protect you child, there is no need to hide them from everything.
Your child isn't as innocent as you think.
Kids grow up fast these days.
Teens here all sorts of language, teens have sex, they see the drinking/drug taking in society.
You just have to trust that you raised them to make sensible choices.
Long story short, its a good movie. Your kids won't be as shocked as you think.