When she started to step back, he tightened his fingers.
She tightened her fingers a little, holding on to him.
Then she tightened her fingers about his and said, "One day, you won't have to."
She tightened her fingers in his with a reassuring pressure.
She tightened her fingers on his briefly before drawing away.
He tightened his finger on the trigger just as he'd been taught.
Gary's words came back to me and I tightened my fingers around the railing.
He took her hand, tightening his fingers on hers when she would have drawn away.
Conrad tightened his fingers on hers, then let her hand go.
Then she pointed it at me, tightened her finger on the trigger.