mouthpiece idea and idea protection

i have an idea for a product that uses a mouth piece with air intake and exhaust work to do.
how do i go about talking design with someone while protecting the overall idea from being stolen.
if there is a thread that already dives into the process please point me to it and i’ll take this one down if it seems redundant.


This thread comes to mind: Patent questions

Also, you can search for “non-disclosure agreement”. You could go to a lawyer and have one specifically drawn up, or use a template.