But where should those lines be drawn?

The easiest ones off the bat are pedophilia, torture, murder etc as I already draw lines with EVERYONE on those grounds

After that, get into the murky realms of emotional manipulation, it's easier to do with guys than women as this is their main weapon so it needs to be at least at a level that catches all the 'honey traps' and sadistic manipulators but not low enough that we're hitting mothers guilt tripping their children to clean their rooms and do their homework.