pleasure oneself

Olds and Milner constructed new experiments that allowed the rats to press a lever. Each time the lever was pressed, an electric current stimulated the pleasure centers of the rats' brains. The rats would go into a pleasure-seeking frenzy, pressing the lever as many as 2,000 times an hour. They would ignore food and water, working themselves into a state of exhaustion and starvation. Eventually, they would die. They literally pleasured themselves to death.

Eleanor pressed her fingers to her lips as Henry grasped his thick shaft and began to pleasure himself. What on earth was she doing standing there watching something so intimate, so private? She felt ashamed and excruciatingly embarrassed ... and yet she couldn't tear her eyes away from him.