As those demands continued, they could be increased gradually in a way that they could still be accomplished by that person, and so that they could be eased into it.
They would keep following those demands as they gradually increased what they would have to do or give until they reached a point where they went past their usual limits of what they would be unwilling to do or give up.
It would be like they had already done so much or given up so much so far that another small increase to those things would not seem like much to them, compared to how they would be suddenly given a large increase to it all, making them hesitate whether they would go that far.
If such a person were demanded to do something beyond their limit of what they could take, then they would be more likely to act out of the control of the person who was making such demands of them.
