This is a really cool fandom-related post I found on tumblr.  It’s about shipping, but this could apply to anything fandom-related:

what is okay:
• to be uncomfortable with a ship
• to hate a ship
• to be disgusted by a ship
• to have reasonings behind it
• to explain your reasonings behind it

what is not okay:
• to tell shippers to kill themselves
• to tell shippers they’re disgusting
• to intentionally harass shippers
• to be a dick to someone because of something that makes them happy