Idiom
draw the line at doing somethingdraw the line at (doing something)
to decide you will not do something.I love vampires, but I draw the line at attending some silly Dracula convention.Where to draw the line on treatment for people who are dying is a decision made by patients, their families and their doctors.
Usage notes: often used to say you will not do something because you think it is wrong:
I'm a loyal employee, but I draw the line when I am asked to do something I think is wrong.