don't go there

English edit

(idiomatic, informal) Do not broach that topic.
- 2009, Emma Darcy, Sara Craven, Diane Hamilton, The Italian's Love-Child (Mills & Boon By Request):
  'Surely, in hindsight, you realise she was an unsuitable wife for you,' he stated unequivocally.
  'Don't go there, Dad,' Luc warned, hard ruthless steel in his own eyes. 'You've lost one son. You're very close to losing another.'

do not broach that topic