The world is filled with people with strange fetishes, but even considering the Intertubes' jaded standard, this particular fetish is really, really, really weird: behold the Woolies, people who like to esconce themselves in wool. Itchy, scratchy wool.
No actual nudity, though there are some - um, how shall I say it - knitted private parts: Link (original link in French at Doctissimo) - via Rue The Day! and Laughing Squid
The heavy wool "enclosure" or "itchy" thing is often mixed with bondage, another very creative outlet for the sweater lover, in that sweaters can feel "restrictive" as well as comforting, and the itch can be a part of the humiliation and suffering, all very creative and intense when practicing with a loved one. Most people who are on this level are far above the madding crowd of conservative party poopers and boring losers who spend their time name calling and making fun of things they fear or don't understand.
Most of you really need to read up on all of this and broaden your erotic horizons or the next time you meet a new lover your conservatism, ignorance of fantasy and role play and fetish and your judgmental behavior, is going to put her to sleep.