What is Draw The Line?
1.
to point out a borderline when the actions of one stop being fun and become hard to stand, irritating, etc.
At first I thought her laughter was sweet, but hearing it for nearly half an hour, that's where I draw the line.
I could stand her not reaching orgasm but when she screamed the name of my friend in bed, that's where I draw the line.
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2.
To get to the point, or finish something, or stop fooling around, to reinstate a rule or action.
It's time to draw the line