2 sets of AR glasses, hit play at the same time. I'm a little bit obsessed with AR glasses at minute. In all seriousness though if you're on a Mac you can use

2 sets of AR glasses, hit play at the same time. I'm a little bit obsessed with AR glasses at minute. In all seriousness though if you're on a Mac you can use SoundSource by Rogue Amoeba to route audio. So if you were streaming something on Netflix, you might be able to connect two sets of bluetooth headphones to the Mac, open Netflix in two separate browsers, route one browser's audio to one set of headphones, route the other's browser's audio to the other set of headphones, hit play on both of them and then just maximise the window/AirPlay the one that is in the native language (because it probably doesn't make much difference if the picture is a few ms out for the one with the dub). Hacky, and there's probably something better out there, but it's low effort and would probably do the job. Dependent on you being in the Apple ecosystem though.