不甘示弱

bùgānshìruò
(idiom) not to be outdone

CEDICT

to be unwilling to be outdone; not to be outdone

Wiktionary

不情愿表现得比别人差。

重編國語辭典

Entry Composition

1 不甘 bùgān
  1. unreconciled to
  2. not resigned to
  3. unwilling
2 示弱 shìruò
  1. not to fight back
  2. to take it lying down
  3. to show weakness
  4. to show one's softer side