Oh, yes, that yelp was certainly welcomed. To make up for the pain, even if he'd enjoyed the reaction, the Doctor leaned down to give that same nipple a quick lick, only to move over and actually bite down on the other. Well, he didn't want to become too predictable, even if he at least kept the stroking of the Master's cock nice and even. He loved how easily the Master appeared to be losing his train of thought due to pleasure, unable to focus on anything but whatever he did to him. Still, the question was asked and so the Doctor answered, maybe even against his better judgment.

"It happened. Trust me, I'd not have thought that up. A whole year and mostly you sulked over me not talking to you." Which, honestly, he didn't think he should be blamed for at all, given the circumstances.