When I was 21 I joined a big band that had people from their late teens to their mid 70s. I think of everyone in that band as something like family, and it was one of the most enriching experiences of my life. Like all friendships, it’s case by case. There are shitty people and there are cool people. Your son is an adult and has to learn to distinguish between those. We do live in a world where inter-generational friendships are rare, and maybe that means that there’s a higher chance that this guy is odd, but to foreclose on inter-generational friendships seems pretty impoverishing. This guy’s background and life experience is probably really different from that of your son. Developing close friendships with people like that is important. Had I not, especially at a young age, I’d be a very different person.
Or he could be a weirdo 🤷
There’s the old joke that metalheads are nice people pretending to be mean, while hippies are mean people pretending to be nice.