My guess is that he's a lot younger than he expected. But that isn't really much to collapse onto your knees for. Anyone can sound any age on the internet. When I was 13, I thought a former close internet friend was like, a full grown adult because she sounded really mature and sure of the world, but as it turns out, she was just a pontificate and like only five years older than me (also kind of a bitch). So while I think that MIGHT be what he's reacting too, it is the internet, and he fully admits he didn't know everything about Mr Fahrenheit's life, so he shouldn't be THAT surprised. So I'm not fully committed to this.
I really hope he's not a fucking child though because fucking children is bad. Like, this entire series had a lot of this, but it doesn't explicitly say it often enough and I feel like we haven't stressed this enough but FUCKING CHILDREN IS BAD. Doesn't matter if you're gay or straight DON'T FUCK CHILDREN
I would guess something gender related, but I would hope not just cause two chapters is not enough time to adequately delve into that, especially for a character that is already dead.
Maybe we just don't have enough imagination or are just imagining the worst. Could be something in the picture rather than Mr Fahrenheit himself