Xander stays invisible, but ups the ante

Both girls' eyes were closed as Willow bounced up and down on Tara's new cock. Xander wandered invisibly around the bed, taking the sight in from as many angles as possible. The two witches grunted and moaned asynchronously. Xander closed his eyes and listened to the sound of their groans, the squeaking of the bedsprings, and the slapping of Willow's ass against Tara's thighs. The sound was as erotic as the visuals.

When he opened his eyes, he saw Willow's little bag, lying discarded and forgotten on the bed next to the two lovers. Picking it up and looking at the dust inside, he got a clever idea. "Two cocks must be better than one," he said, issuing a mental command to keep the girls from noticing his comments. "Or maybe I should say that three cocks are better than two," he ammended.

He pulled a pinch of magic dust out of the bag and sprinkled it on Willow's cunt as it bobbed up and down around Tara's member. Under Xander's command, Willow uttered the magic words again. He grabbed her clit between his thumb and forefinger, the act of her humping pulling and pushing her bud through his fingers.

There was a moment when Xander thought there would be no change before...