I am 55 and just recently started coming out to my friends and family. It's been a gradual thing. I'm not trying to hide anymore, I just look for the right time.I have a friend of 43 years I am seeing next week for lunch. I only see her about twice a year so am not sure if I will tell her or not. For me, it depends on how often I see the person and also if my illness has or might affect them.
One of my good friends has bipolar and she told a neighbor she didn't know well. The husband of this neighbor came over later and said "I think you have a demon inside you." This sort of scared me off of telling people I don't know well. And frankly, my mental health is not everyone's business.
In your case, however, I probably would have told this friend. He sounds pretty nice.