Spock's chest tightened at her touch and his brow furrowed. He kept his gaze focused on the countertop in front of him. His hands rhythmically opened and closed as he focused on his breathing for a long moment. He wanted to jerk away from her, insist that nothing was 'going on', and leave their apartment as quickly as his legs would carry him. He knew that's what he should do, too. Go somewhere quiet to meditate, somewhere that didn't have the never-ending distraction of Nyota so very close and within arm's reach.
Yet Spock also knew that he couldn't, wouldn't, leave. It was part of what had led to him throwing the bowl. As much as logic dictated that he get as far away from the woman with whom he shared a bed nightly, he just couldn't not bring himself to do it. Yet he couldn't speak of what was bothering him either. Not only was it distasteful to speak of such things, as well as embarrassing (and yes, he was aware how illogical being embarrassed was but currently did not care), but he knew that Nyota would want to help and he simply could not allow such a thing.
However he couldn't lie to her, or avoid the question anymore, either.
Reaching up, he gently grasped the wrist of the hand pressed against his chest and pulled it away from him. Without the feel of her warm skin upon his, he could focus a bit better and chanced a glance at her. His dark eyes shone with an obvious internal struggle that was bordering on downright painful; there was a gleam in his eyes as well that, simply put, was all but feral. When he spoke, his voice was quiet yet wavered ever so slightly from obvious emotions he was just barely keeping in check.
"Pon farr."
It hurt, to say the words. Two simple words, words that he was all but certain that Nyota - with all of her schooling in languages - would not even know the meaning of, and it was all but impossible for him to speak them aloud. He managed, though, and after another shaky breath he added, "I am... experiencing pon farr."