Ok so I know it's not healthy or good, but when women are suspicious and need solid proof there's an easy way to see passwords on your partner's/husband's phone.
On a Google search page click the 3 dots top right and check settings, if you know the pass code you can see the passwords for every site.
Men can be awful cheats and the more we can do to expose/avoid this the better! (Speaks bitterly from experience)