Yes

Sam sheepishly got up then got his knees behind Mandy. He was very tempted, but he did not pull her shorts down.

"Good," Dr. Vandersloot said. He paused for a moment, clearly waiting to see if Sam would remain compliant.

"Now," he resumed. "massage Mandy's ass until I tell you to stop. Do NOT pull down her shorts or play with her pussy through them."

Sam planted one hand on each of Mandy's large cheeks and took a handful. He began kneading and spreading them apart, massaging her muscles and trying to spread her holes to pleasure to get her wet.

The massage seemed to do the trick, because Mandy started moaning within a few seconds of feeling his hands on her. His cock throbbed as he felt her body quiver from his touch. He wanted to glide his bulbous, aching cockhead against her so bad. He wanted to make her cum. He wanted her to make him cum. He...

"Stop!" Dr. Vandersloot said. Sam stopped moving, but held onto Mandy tight.

"Very good, Sam," Dr. Vandersloot said. "Very interesting."

"Now," he continued. "Remove your hands." Sam did so. "Mandy, push back against Sam's member. Make sure the entire length moves near your pussy and asshole. Sam you must not touch Mandy with your hands at all, or move your hips to reciprocate Mandy's action. Your cock will instinctively react, but that is the only movement I want to see."

Sam sighed, but stood his ground as Mandy shuffled back, then backed her ass up to the base of his cock. She shook her moneymaker, moving his dick into groove between her cheeks, then lifted it up slow, tugging his cock and making him ache. When she got to his tip, she let it rest in the cleavage between her ass cheeks, then started twerking. One cheek jiggled, tickling his cock. Then the other. Back. And forth. It took all of his willpower to stay still. He want to slide his pole up her backside so much. He wanted to flip her over and thrust inside her and make her squeal.

But he sat there, struggling. Straining as she moved her soft butt back down the length of his cock again. Teasing him, tempting him...