The boy is feeling his enforced chastity so much more, the longer Mistress denies him.
How can Mistress be so dismissive of his needs, to touch, to play. to edge her cock, to feel the immense pleasure of an orgasm, he hears her having them often enough, but, its not about the frustration the boy feels at times, all the time, its about handing his submission to his Mistress, giving her the control she wants to take from him, of him, in the only way she can at the moment.
That feeling of her having control in the way she does, does frustrate the hell out of him, but, he also loves being controlled in such a way, of Mistress telling him she doesn't count, she, doesn't have to, she can pleasure herself anytime she wants, unlike the boy, who gets his pleasure when she decides, if, she decides at all.
At the moment the only time the boy gets to touch his self is when she is torturing her cock, and does she like to do that from time to time, but again, it shows the boy, its her cock, and, she will do whatever she wants with her cock, and when she wants to. !!