That sinking feeling after you blow your load, when you look at the porn you've been jerking off to and wonder why you got off on it. Usually applies to fetish orientated material.
The feeling usually subsides minutes later.
*spooge* "....Why the bloody hell did this picture of woman rubbing socks on herself get me off? Man I'm weird. I should throw this stuff out."
*5 minutes later*
"Shit, why did I throw that out? That picture was hot!"