The odd exploratory finger here or there during the act is not 'rape' or 'sexual assault', it's just part of having sex. Life would be rather joyless if we had to memorise a list each other's do's or don'ts that had been established beforehand.
Mind you, the strangling thing was odd. She'd stop when asked, but once she'd got back into it, she'd absent-mindedly start strangling one again. It was really quite irritating.