Why are you letting your friend ruin your kink? I'm only familiar with half of those four fandoms, but they're fairly healthy relationships, although not sexual in the canon at all - which means they could possibly serve as the basis for healthy sexual relationships in fic. You clearly believe your friend's relationship is completely different.

That said, you should talk to your friend. I don't want to assume anything, but depending on ages and your country etc etc there is potential for major trouble down the road.