Vubben's eyestalks contracted involuntarily as the Egg once again made its presence known.

Ziv closed his eyes and involuntarily contracted his neck muscles.

Muscles that hadn't bothered him for more than an hour involuntarily contracted as he took off his shirt and trousers.

Her muscles contracted involuntarily, wanting what he wouldn't give.

"The doctor said sometimes their muscles will involuntarily contract when they are in this state."

Then my stomach muscles contracted involuntarily, pulling me halfway upright again.

Her hand contracted involuntarily on his shaft, a delicious death grip.

Her legs were shaking as the muscles contracted involuntarily, trying to rid themselves of the paralysis imposed by the stunner.

During such an episode, the bladder may be contracting involuntarily, causing urine to leak.