Disclaimer: the behavioral theories described briefly here are bullshit.
Vegeta was trembling. He always did that when he was restrained. Goku was sure it wasn’t fear; just frustration and helpless anger. But Bulma insisted the problem was an inability to relax and trust in others, so she kept coming up with those weird machines and exercises. Goku didn’t understand how wrestling the poor guy into immobilization every single day was supposed to teach him how to relax. Then again, she was the expert.
The trust part made a little bit more of sense. Lying was absolutely forbidden, so every promise had to be fulfilled, be it a threat of a savage spanking or the surrendering of a magnificent reward. It didn’t matter how helpless he was, the outcome of their sessions would be always predictable. And to a certain extent, also up to Vegeta himself.
Though, and like a fight, the end did justify the means. And though he had tried to deny it, Goku loved walking that fine line between abuser and diligent attendant.
“…what are you doing..?”
Goku’s blinked, immediately snapping back to the current session: was there a hint of fear in Vegeta’s gruff voice? Maybe the blindfold had been too much. There was an empathic urge to remove it, but curiosity was stronger. Was he afraid of him, or Bulma was right, and he was incapable of dealing with helplessness? That changed so many things…
“Just standing here…” Goku informed. “Want me to do something?”
“…how about you release me, you…” He stopped himself abruptly, clapping his mouth shut. A particularly violent shiver shook his body. “…Master…”
Goku shivered too. It made him feel a bit guilty, but he hoped Vegeta would make a habit of calling him that. Even if it meant his main excuse to spank his stocky little ass would disappear.
“No.” He knelt in front of him. Vegeta had to know where he was, but there not what he was doing wiith his hands…or what weapon was about to be used on him. That was amusing, for some reason. “Not yet…”