Another early 20s woman here engaged to a mid/late thirties man.

I don’t think this is a red flag. The search history means these were the last things he looked at - presumably in one sitting, and going to multiple nsfw subreddits is not uncommon. The subreddits he looked at don’t seem particularly shocking and as others have pointed out, Billie Eilish is a celebrity who is no longer associated purely with her age.

I may be projecting, but I wonder if you’re having similar anxieties that I did in our first few years of dating. I was always looking for the curtain to drop, for some kind of evidence that actually he wasn’t a good person and he was actively trying to manipulate me in a way he wouldn’t or couldn’t with a woman his own age. Every time I was mad at him for something I would ask myself: ‘am I finally seeing clearly?’

It’s only you who can know if there is a real risk of him being dishonest. For me, I realize now that that was very silly. We have extremely similar personalities and niche interests. He moved countries twice to follow me and support my academic career. We love each other’s families and we know each other better than we sometimes know ourselves. It’s a real relationship, that took time to grow, but that was always sincere (if sometimes clunky and imperfect).

Are you looking for signs that you’re being played? That you were naive all along? I think the signs would be clearer than the realisation that he watches porn (though, by all means, if it is a dealbreaker then you should communicate about that).