On impulse he went in and told him the whole story.
On impulse he went to the front of the car.
On impulse she decided to go down and see him for a moment before going to bed.
He turned to leave her, on impulse she stopped him.
The kitchen door stood open and on impulse she went in.
Sometimes it's not a good idea to act on impulse.
On impulse, she decided the time had come for larger game.
Perhaps on an impulse he'd taken over a life, and wasn't sure what to do with it.
On an impulse he reached up and held her hand.
On impulse she ran back down the hill, all the way to where he stood.