sheer

http://futaomnom.tumblr.com/post/93743035927

“Shear” means to “cut, tear, or stretch”, or (as an adjective), something related to those actions (“shear stress”).

“Sheer” (as an adjective) means either “pure; utter” (“sheer failure”) or “thin and transparent” (“sheer fabric”).

I think the image caption should be “Sheer Pleasure”, as it could refer to either the fact that the pleasure is pure and total, or the fact that the fabric of the dress is sheer, leading to pleasure.