Stop Automatic Calling when Screensharing

I screenshare a lot in my position; I call the coworker (Phone/Headset) and train them on what I need them to look at. I am in a large office building, and the automatic calling of the receivers' PC is disruptive, as I do not was the whole office to hear my conversation or have people hear my trainee. I see no way to disable the team auto-call once I start to screen share or in the Options. All my coworkers feel this frustration as well.  I do use the computer microphone/speaks aspect when working from home, but would disable it totally, if it would stop the auto-call.  I do not want it to affect meeting invites to others, as others around the country can use their PC speak/microphone, if they want. Please advise.