IN PROGRESS
First of all, that it is a real shame.
Narcissists can be charming and funny and generally good company, which is why it can take a long time for you to realise that your friend is one, and the decision that you cannot and will not handle a friendship under those cicumstances, is a painful one to make.
I am not a mental health professional in any way, shape or form, and therefore the below is only based on my own personal experience, what I have learnt communicating with others about it, and what I have been able to find when researching on-line.
How to recognise a narcissist:
An overwhelming sense of self-importance, often resulting in them expressing themselves in unbelievably pompous ways.
A compulsion to be hurtful and/or rude towards other people, and when you try to find out what that was about, they have fits of anger, turning everything around and ending up expecting an apology from you. It Is as if they can only behave “normally” for so long, and then they need to let off some steam.
Everything is about them. Example: When you owe them money, they will remind you, but the other way around they quickly “forget”. Same thing when you lend them a selection of things to try out – none of it is returned.
Another example: When they go on trips, they do not send photos, but whine when you go somewhere and do not send photos (even though you – unlike them, funnily enough – always place photos on instagram and Facebook).
They are slight hypocondriacs.
When they are good company, that is all acquired skills. They observe so-called “normal” people to see how they behave in everyday situations so that they can emulate that in order to become part of people’s lives. As someone more knowledgeable on the subject than me said: You might as well spend time with a robot. At least robots do not deliberately hurt and insult people, and they do not have fits of anger and rage at the slightest questioning about or criticism of their behaviour.
They will never, ever, own up to having any kind of mental health issues. If only they would, then you could have a civilised conversation about it, and you could listen and learn, and there would be some hope of preserving the friendship.
But again, everything will be turned around and for a long time, you will actually believe that all incidents of discord was your own fault. Until you decide to dare to think “narcissism” and start educating yourself about it.
Alas.