This puts Romeo in a position to notice, and be aroused by, her arousal at being sensed by him. He senses that she senses that he senses her. This is still another level of arousal, for he becomes conscious of his sexuality through his awareness of its effect on her and her awareness that this effect is due to him. Once she takes the same step and senses that he senses her sensing him, it becomes difficult to state, let alone imagine, further iterations, though they may be logically distinct. If they are both alone, they will presumably turn to look at each other directly, and the proceedings will continue on another plane. Nagel, Sexual Perversions
And yes, he does later compare this to Gricean reflexive intentions in communication.