Hi putergod,
I'm Rodrigo, Independent Advisor and I will help you.
Windows does not have a way to output audio to multiple devices, in the link below you can see a workaround to output audio to 2 devices at the same time.
https://answers.microsoft.com/en-us/windows/for...
Another way to do that is using a software solution, like Voicemeeter, the Banana and Potato versions allows you to output audio to 3 and 5 devices respectively.
https://vb-audio.com/Voicemeeter/
Note: This is a non-Microsoft website. The page appears to be providing accurate, safe information. Watch out for ads on the site that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the site before you decide to download and install it.