I need advice!

Okay so a couple of weeks ago I met a guy at a small gathering of one of our mutual friends and we really hit it off. We had such a good talk for hours and at the end of the night we shared social media. Keep in mind that the conversation was not flirty or romantic at all, and was actually extremely gruesome and morbid.

So we started chatting online and I got the distinct feeling he was flirting. He asked if I was single, and one point (when I was out and said I was dressed up so it wasn't creepy) ask what I was wearing in an awkwardly flirtatious manner. There was other stuff too. The mutual friend whose gathering it was told me at a party that he thought I was 'cute' and thought I had a nice laugh. She said I should contact him and 'see what happens'

The problem is I am not at all interested in being anything but friends, and the idea that he is interested in a romantic way makes me extremely uncomfortable. I have never felt romantically about anyone and never particularly want to - I don't want to date, get married, nothing. I'm not interesting in anything romantic. I want to further my platonic relationship with him because he is such a cool guy and we have so much in common but I feel like I would just be furthering his feelings and I honestly can't stand the thought. I'm also worried that he won't value our connection as much when he realises it won't ever turn romantic. Most people have this idea that romantic relationships lead to a stronger connection and are more meaningful and so put far more effort into them than into platonic ones

I don't want to directly ask him but I was wondering if there was a way to hint at the fact I'm not interested? Do you have any advice?