be on someone's back
US /bi ɑn ˈsʌm.wʌnz bæk/
UK /bi ɑn ˈsʌm.wʌnz bæk/

1.
mengomel, mengganggu
to constantly criticize or nag someone
:
•
My boss is always on my back about deadlines.
Bos saya selalu mengomel tentang tenggat waktu.
•
She hates it when her parents are on her back about her grades.
Dia benci ketika orang tuanya mengomelinya tentang nilainya.