I think xhamster or one of those pages, they have AI subtitles I believe. They automatically pick up the language and give you English subtitles by default.

Edit: to clarify, I don't usually pay attention to the dialogue unless its unscripted amateur stuff. Two porn actors reading the corniest lines possible? Fuck no. A random-ass couple being perverted and uploading themselves online cause they're pervs, and you can hear their perv talks? Fuck yes, sign me the fuck up, let's all be pervs together, the way Lenin intended.

Pornhub offer the service if I am to believe their help page ah hum

Why would you want subtitles? The dialouge is only...

"Oh my fucking god!" "Fuck my ass!" "You want to cum in mommy's pussy?""Don't cum in me. I dont want to get pregnant." and"but you're my step sister!"

I always had the impression that porn sites had a different purpose other than reading. But probably that's just me. /s

Real talk: Some porn has (ai) subtitles, some doesn't.

Even before auto generated subtitles, porn subtitles existed. It's quite uncommon, however. I remember a "vintage" gay porn about two guys in a barn which had subtitles.

[macaroni sounds]

This isn't "questions" in the shower. Bugger off with this crap.