Have I just disocvered something new?

@The_Fury: I think you are 'onto something.' Perhaps this is temperature modifying how we sense and interpret the position, size and shape of objects as they open the anus and enter or reside in the anal canal.

I think I've felt that effect during the small, shallow canal-douche I use before an Aneros session. Althugh the low pressure and flow rate from my Shower Shot are both very repeatable the temperature is uncontrolled and does vary far too much. As it warms or cools my sense of the shape and bulk of the douche nozzle tends to also change.

Perhaps the output from nerve endings that sense contact pressure isn't linear as temperature changes. (just a wild-assed guess)

My impression is that the pleasure effect of the douche is best just a few degrees above my body temperature. (That seems to allow the inner sphincter to open and admit the water into the rectum.)

Several years ago, When I was first adapting to larger toys like the Progasm, my inner sphincter would tend to spasm and assume a 'brick wall' stance. Warming the toy before another 'try' sometimes yielded an easier insertion.

If this characteristic is widespread one can ponder the evolutionary or 'creative design' rationale that yielded this characteristic.

Perhaps we evolved or were designed to accept, perhaps crave, body temp objects and to reject hot or cold 'foreign' objects.