Narcissists really don't feel about you the way you feel about them. And even if they actually do it's only temporary until someone else catches their eye. This might take years if they really like you. But then...they will go after that. Keep in mind your relatively safe as long as you don't get married and get a bit predictable. They can play all the games they want after that. Then they are the ones temporary and replaceable. Let them change their minds all they want. You don't pay them when they leave. That money is saved.