sink to somebody's level

sink to (someone's) level

To behave as badly, immorally, or basely as someone else, especially in a dispute or conflict. Don't hit him, Tom, just walk away; don't sink to his level. We'll have to sink to their level if we're going to stay competitive in the market.
See also: level, sink
Farlex Dictionary of Idioms.

sink to somebody’s ˈlevel

stop behaving well and begin to behave badly, especially in an argument or a fight, because other people are behaving in this way: Use words, not violence, or you’ll just be sinking to their level.
See also: level, sink
Farlex Partner Idioms Dictionary
See also:
  • don't get me wrong
  • don't beat a dead horse
  • all in (one's) head
  • discipline
  • discipline (one) for (something)
  • discipline for
  • don't @ me
  • come it
  • come it (with one)