Is it possible for two people to watch TV while each has ear phones or head phones with their own independent volume control unaffected by TV volume control or whether TV speakers are turned on or off?
Or the tvs digital audio out via optical/toslink/spdif to a dac with an optical input, though sometimes with this route you either need to make sure the tv outputs stereo pcm over the optical output, or the optical dac has an ac3/ac3+ decoder builtin.
From the optical dac you could use a stereo rca cable to 3.5mm stereo cable and connect to that behringer amp, or use rca splitter cables to separate amplifiers, or use an optical splitter be fore the dac and connect to separate dacs and amps.
You could do all this with bluetooth as well.
And you can work in devices that perform real time binaural rendering(5.1 to binaural stereo i.e. surround sound) like the soundblaster portables.