I have a dozen devices from Sonos/Google/Apple/Samsung/LG and a duo plan.

[Hans_Schulze]

I can't seem to play music for my wife, then leave the house on my phone and play something else. Why can't we be allowed two streams under a Duo account before it gets stopped? I found a thread that was years old discussing this, was closed without root cause or suggestions besides manually logging off and on, which is horrible for shared devices. Even worse when an automation script starts from the cloud.

[aecid]

You have a DUO Plan, which means you can invate a second account to your plan. It does not mean you can stream two songs simultaneously with the same account. 

You have to invite your wife in your profile settings