In a Shakespearean sonnet, a couplet consists of two consecutive lines that typically rhyme. In "Sonnet 116," the following lines form a couplet:
“If this be error and upon me proved,
I never writ, nor no man ever loved.”
So, the correct response would be either version of the couplet provided:
“If this be error and upon me proved, I never writ, nor no man ever loved.”
or
“If this be error and upon me proved,
I never writ, nor no man ever loved.”