Sometimes he paints his knee or thumb in a corner of the picture to make explicit that he's there.

His thumb made a circle against one of her fingers.

He examined the marks and decided that the left thumb made the clearest impression.

His thumb made a slow arc across her skin.

When his thumb made a slow pass across her skin, her pulse jumped beneath it.

She looked down at herself as her thumb made a pass across the uppermost button.

His thumb made lazy circles on the back of her hand.

His forefinger and thumb made a small sign between us.

Oliver balled his fist, thumb extended, and made an upward movement.

His thumbs made two circular paths at the base of her neck.