The degree to which a person can grow and heal is directly proportional to the amount of the truth they can accept about themselves without running away.
Narcissists DO NOT love. They use. Love is their word for use. Just replace love with use and it all makes sense. "I use you. I use you so much. I will always use you. I will never use anyone as much as I use you. You are the use of my life. I will use you forever.
Personally, I don't find swearing offensive. I do find backstabbing, gaslighting, lying, cheating and screwing people over offensive, but not swearing.