"Good," she said, "Keep going like that then... but don't do anything else without asking me first!"
He nodded, but she didn't see as she was too into playing with herself to notice.
She started to have several orgasms, one after the other. Watching her cum was making him more and more frustrated as he continued to twitch and ache.
At about this time I heard Crystal orgasm, and started listening at the door, without letting Crystal or Tom see me.