I know multiple married couples where there ‘traditional’ boundaries aren't applied; apparent infidelity would not actually be breaking any promises in these cases.

I'm curious why it's only politicians who need to be held to this standard - surely vicars and the bosses of large organizations are recipients of a great degree of trust also. (And for that matter sportsmen/women ‘in the field’ - their fans and team-mates trust them not to e.g. throw a match.)