draw the line at

draw the line at (something)

To refuse or decline to do something or take further action. I'm not opposed to cleaning our apartment, but washing your dirty dishes is where I draw the line.
See also: draw, line
Farlex Dictionary of Idioms.

draw the line at

Refuse to go any further than, as in I draw the line at giving them more money. This expression alludes to a line drawn at a stopping point of some kind. [Late 1700s]
See also: draw, line
The American Heritage® Dictionary of Idioms by Christine Ammer.

draw the (or a) line at

set a limit of what you are willing to do or accept, beyond which you will not go.
1995 Kate Atkinson Behind the Scenes at the Museum She even manages to persuade Gillian not to cheat…although Gillian draws the line at not screaming when she loses.
See also: draw, line
Farlex Partner Idioms Dictionary

draw the line at, to

To set a specific limit, particularly on one’s behavior. This expression, heard in such contexts as “He drew the line at outright cheating,” comes from drawing some sort of boundary, but no one is quite certain as to what kind. Some speculate it comes from the early game of court tennis, in which the court had no specific dimensions and the players had to draw their own lines. Others believe it signified a line cut by a plow across a field to designate the property boundary. The term was used figuratively from the late eighteenth century on and was probably a cliché by the time W. S. Gilbert wrote, “I attach but little value to rank or wealth, but the line must be drawn somewhere” (H.M.S. Pinafore, Act I).
See also: draw, line
The Dictionary of Clichés by Christine Ammer
See also:
  • draw the line at (something)
  • all y'all's
  • if that's not (something), (then) I don't know what is
  • have no use for
  • have no use for (someone or something)
  • have no use for somebody/something
  • agree to
  • How much is (something)?
  • a bone of contention
  • bone of contention
References in periodicals archive
However, I draw the line at promoting a celebrity who deems homosexuality a sin.
OK, I draw the line at Big Brother--and I'm ashamed of my sneaking weakness for I'm a Celebrity, get me out of here!,
Tony Blair: "You draw the line at anything that's improper and you have to have a system of accountability.
I simply draw the line at speaking Spanish in a business that is on U.S.
Lewis, who acceded to similar demands by Evander Holyfield before their first fight on the basis that Holyfield held one more title than him, would draw the line at Tyson getting paid more.
However, it seems they draw the line at Grouse, at least on the Scottish rugby team's jerseys.
Opposition to the opening in Congress might yet stop the plan in its tracks, particularly if traditionalist-minded members of Zedillo's own ruling Institutional Revolutionary Party (PRI) draw the line at opening the energy sector to foreign investment.