unsmirking
/ˌʌnˈsmɜːrking/Definitions
1. adjective
unfailing in a smile or a polite expression, showing no sign of emotion
“The politician’s unsmirking demeanor was a relief after the previous day’s scandals.”
2. noun
the state of being unfailingly polite or serious in expression
“Her unsmirking was impressive, especially given the tense atmosphere of the meeting.”