"It will suffice," he says, meeting her eyes.
He doesn't thank her; it is a precaution that should be taken regardless, and her particular phrasing doesn't escape him, nor the fact that it was only him giving his word.
Other options:
no subject
"It will suffice," he says, meeting her eyes.
He doesn't thank her; it is a precaution that should be taken regardless, and her particular phrasing doesn't escape him, nor the fact that it was only him giving his word.