I had the exact same problem until i found a maxim in Ray Dalio's Principles.

The maxim is, "Have good structures in place, and you won't need to worry about the trust of others"

A good "structure" means have a proper legal and adminstrative setup.

Basically, clearly outline the worse case scenarios that your partner, co-founder, employees may display then, make it upfront on how you will deal with it i.e the consequences