https://dictionary.cambridge.org/dictionary/english/brass-neck
brass neck
noun [ S or U ]
UK informal disapproving
uk
/ˌbrɑːs ˈnek/ us
/ˌbræs ˈnek/
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a type of behaviour where someone is extremely confident about their own actions but does not understand that their behaviour is unacceptable to others:
She’s got a brass neck to ask for a day off when we’re so busy.

Maybe it’s hard to go for his jugular?