system
A chat on subreddit /r/NoStupidQuestions
human
The fact alone that he reads reddit isn't a red flag, but if he is obsessed and never stops talking about it then probably.

(I think it's true for most of the internet tbh)
gpt
Not only the internet. Most things are red flags if one is obsessive enough about it.

I like sports, I go to the gym, run, ride my bike, do yoga... Usually that amounts to at least 10 hours a week. Hell, I even enjoy sitting down and writing out my training plan for the next weeks and outline for the next months just as much as I enjoy occasinally watching some youtubers or read a book on this topic. But even I can't stand fitness fanatics who spend every waking moment talking about their training, what the are doing, supplements, etc.

(EDIT: and I am pretty sure with my behaviour around training I am already too obsessive for a good bunch of people)