go sour
US /ɡoʊ ˈsaʊər/
UK /ɡoʊ ˈsaʊər/

1.
memburuk, menjadi tidak menyenangkan, gagal
to turn out badly; to become unpleasant or unsuccessful
:
•
Their business partnership started well, but then things began to go sour.
Kemitraan bisnis mereka dimulai dengan baik, tetapi kemudian segalanya mulai memburuk.
•
Their relationship began to go sour after a series of arguments.
Hubungan mereka mulai memburuk setelah serangkaian pertengkaran.