Absolutely nothing

The doors had slid open alright, and three sets of footsteps could be clearly heard in the echoy room, but nothing appeared to come through the door. James checked to either side, and sure enough there were alien-like creatures approaching the two other men, and moving straight into the space between the other men's spread legs. But nothing, nothing was approaching James.

And yet, something, something seemed to be touching him! In his already stretched hole there was a slight sensation, growing stronger and stronger now that James had noticed it. James kept looking down, in disbelief at the absence in the space between his legs, but he was absolutely convinced that there was something inside him, somehow growing longer and slowly, slowly wider as well.