Play Audio from Two devices at the SAME time.

Hey everyone! I have a pair of Sony WH1000XM4 headphones which I've had for a couple of years absolutely love. And the fact that you can pair to two devices at the same time is very useful, however, I'd like to play audio from both those devices at the same exact time. Is there a way to do this without one device taking priority?

For context, when I'm gaming I have my game on my PC and I like to watch a YouTube video and/or Netflix show on my phone while I'm playing for some background noise. However, having headphones on means I can only hear one program at once. But knowing that the XM4's can connect to 2 devices I figured it would allow me to hear both devices at the same time, however I cannot seem to find any information on if this is possible. Every time I search for information it only brings up how to pair to two devices not play sound from two devices at the same time.

Does anyone know about if this is possible? Thank you!