"So does yours." Keenser smirked back, with a meaningful nod towards the unmistakable bulge in Kirk's pants. He sighed and leaned into the touch. "Careful of the purple," he warned. The small, infrequent blotches of purple along his spine, chest, and lower extremities were his aural structures; exposed to the open air as they were, he could feel every tiny air current, every vibration and hum of the ship, two sets of heartbeats as human blood pulsed through human veins, and the tiniest hitch in Scott's breath.

Direct contact to his aural structures could easily become uncomfortable, disorienting, painful. Anything more than the most delicate of touches hurt.

Safer to touch was the green flesh of his photosynthetic structures, or the blue patches that were his heat-sense. Both were sensitive, but not overly so.