Gymnophoria - The sensation that someone is mentally undressing you.

He is checking the equipment in the cupboards – moving big boxes, bending down, standing up – down in the cargo bay when he feels it – that tell-tale tingling in the nape of his neck, the unnerving, uncomfortable feeling of being watched (he is too well familiar with this feeling; also, his keen ability to actually sense being watched has saved his life a couple of times).

He is alert right away – it's an instinct that kicks in sooner than rational thought. His muscles tense up, ready to attack or defense and his gaze wanders to the side, checking if he has his gun within reach. Then, only then, does he turn around and look up.

Skye's up on the gallery, her elbows resting on the railing, looking down at him with wide, unwavering gaze.

He relaxes instantly and gives her a slight smile.

She returns it and licks her lips; he sees her eyes slowly move along his body, studying him slowly.

He can practically feel his clothes being peeled away. The sensation is quickly setting his blood on fire.

He grins, his gaze challenging.

She makes a small, come-hither gesture with a single finger, slow, seductive, then turns around and disappears into the main deck of the Bus.

He doesn't have to be told twice to follow.