unmitigated gall(focuses on the shocking nature of the behavior, often due to a lack of respect or decency: The thief had the unmitigated gall to return to the scene of the crime Taras)
unashamed arrogance(highlights the lack of shame or hesitation in being rude or demanding: His unashamed arrogance was off-putting to everyone in the room Taras)
barefaced cheek(implies a blatant disregard for social norms or expectations: The actress' barefaced cheek in demanding special treatment was met with disgust Taras)
audacious nerve(focuses on the sheer audacity of someone to act in such a way: The burglar had the audacious nerve to leave a note thanking the homeowner for not being home Taras)
unconscionable rudeness(highlights the unacceptable and hurtful nature of the behavior: The customer's unconscionable rudeness to the waiter led to him being asked to leaveTaras)
